Initial European Aviation Community Feedback on the GALILEO Mission by qor17644

VIEWS: 9 PAGES: 72

									       EUROPEAN ORGANISATION
   FOR THE SAFETY OF AIR NAVIGATION


                                                    EUROCONTROL




     Initial European Aviation
   Community Feedback on the
  GALILEO Mission Requirements
       Document (MRD) V5.3




                   Edition Number   :               1.0
                   Edition Date     :     16 April 2004
                   Status           :   Released Issue
                   Intended for     :   General Public




EUROPEAN AIR TRAFFIC MANAGEMENT PROGRAMME
  Initial European Aviation Community Feedback on the GALILEO Mission Requirements Document (MRD) V5.3



                          DOCUMENT CHARACTERISTICS


                                               TITLE

      Initial Aviation Community Feedback on the GALILEO
           Mission Requirements Document (MRD) V5.3
                                                  EATMP Infocentre Reference:         04/04/21-01
                   Document Identifier                          Edition Number:       1.0
                                                                    Edition Date:     16 April 2004
                                                Abstract
 This document provides initial feedback from the European aviation community on the GALILEO
 Mission Requirements Document (MRD) Version 5.3. The objective was to capture feedback from a
 GALILEO user point of view. To this end ECAC State Authorities, ECAC Air Navigation Service
 Providers, Airspace User Associations, IFATCA, IFALPA/ECA, and JAA/EASA have been
 approached for the feedback. The limited time available for this consultation process has resulted
 that not all Stakeholders could provide feedback in time or provided initial reactions. Further
 consultations will take place to ensure the feedback is complete and well addressed.

                                              Keywords
 GNSS
 GALILEO
 Navigation

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 Draft                      EATMP Stakeholders           Extranet
 Proposed Issue             Restricted Audience          Internet (www.eurocontrol.int)
 Released Issue             Printed & electronic copies of the document can be obtained from
                            the EATMP Infocentre (see page iii)




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                      EATMP Infocentre
                      EUROCONTROL Headquarters
                      96 Rue de la Fusée
                      B-1130 BRUSSELS

                      Tel:    +32 (0)2 729 51 51
                      Fax:    +32 (0)2 729 99 84
                      E-mail: eatmp.infocentre@eurocontrol.int

                      Open on 08:00 - 15:00 UTC from Monday to Thursday, incl.




                                DOCUMENT APPROVAL

The following table identifies all management authorities who have successively approved
the present issue of this document.

   AUTHORITY                       NAME AND SIGNATURE                                  DATE


GNSS Policy Office                         Chris Bouman



    Director ATM
     Strategies                             Bo Redeborn




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                           DOCUMENT CHANGE RECORD

The following table records the complete history of the successive editions of the present
document.



EDITION     EDITION   INFOCENTRE                                                            PAGES
                                                     REASON FOR CHANGE
NUMBER       DATE      REFERENCE                                                           AFFECTED




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    GALILEO Mission Requirements Document (MRD) V5.3

      European Aviation Community Views and Comments


                       INITIAL FEEDBACK




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                                             CONTENTS

DOCUMENT CHARACTERISTICS ............................................................................. ii

DOCUMENT APPROVAL........................................................................................... iii

DOCUMENT CHANGE RECORD .............................................................................. iv

1. INTRODUCTION.................................................................................................... 1

2. CONSULTATION EUROPEAN AVIATION COMMUNITY ................................... 1

3. GENERAL COMMENTS........................................................................................ 2

4. SPECIFIC COMMENTS ON THE GALILEO MRD VERSION 5.3 ........................ 5

5. CONCLUDING REMARKS.................................................................................... 8




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1.                    INTRODUCTION


1.1      GALILEO will provide a basic GNSS constellation consisting of 30 satellites
         along with the required ground infrastructure, and is planned to be operational
         in 2008. The GALILEO Joint Undertaking (GJU) is responsible for the
         development of the GALILEO Programme and the selection of the GALILEO
         operator. The GJU is also responsible for ensuring that the GALILEO user
         requirements have been adequately taken into account.

1.2      EUROCONTROL is the focal point for European aviation aspects of GNSS, and
         as such co-operates with the above European institutions to safeguard
         European aviation interests. As such, EUROCONTROL has been requested to
         provide aviation community feedback on the GALILEO Mission Requirements
         Document (MRD) Version 5.3, so as to ensure that, to the extent possible, the
         next version of the MRD incorporates the views from the aviation community.

1.3      The feedback in this document concerns the GALILEO MRD Issue 5 Rev3 (10th
         Oct’03). The GALILEO programme schedule calls for the MRD to enter the next
         phase in May 2004. In order for the GJU to incorporate amendments as a result
         of this consultation process, the feedback was requested to be available by mid
         April.

1.4      This material is not intended to replace aspects of the “aviation community
         position on GNSS” that was approved by the Provisional Council in 2002. The
         feedback provide in this document is specifically aimed at the GALILEO MRD.



2.                    CONSULTATION EUROPEAN AVIATION COMMUNITY

2.1      Because the Galileo MRD V5.3 was a restricted document, due to a number of
         open issues that exist in this version, the document could not be distributed
         without precautions to avoid unwarranted use. After addressing methods to
         satisfy this requirement, which posed administrative problems that could delay
         and hamper aviation feedback, the GJU made available an extract of the
         GALILEO MRD V5.3, which could be distributed without administrative
         precautions. This extract consists of a slightly reduced MRD but with all material
         that, according the GJU, is relevant for the requested feedback from the
         aviation community.

2.2      To ensure representative feedback from an ECAC “GALILEO user” aviation
         perspective, the GALILEO MRD was distributed to:
         ♦ the ECAC Civil Aviation Authorities,
         ♦ the ECAC Air Navigation Service Providers,
         ♦ Airspace User associations,
         ♦ International Federation of Air Traffic Controller Associations (IFATCA),
         ♦ International Federation of Airline Pilot Associations (IFALPA, including the
            European Cockpit Association),
         ♦ Joint Aviation Authorities (JAA) and the European Aviation Safety Agency
            (EASA).




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2.3      Since GALILEO is closely related to the ECAC Navigation developments, the
         basis for the distribution that was used for this initial consultation was the
         membership and contact list of the EATM Airspace & Navigation Team (ANT).

2.4      The feedback received has been consolidated in this document by
         EUROCONTROL, with some additional input based on EUROCONTROL
         expertise. Since the requested feedback distinguished between “general”
         comments and comments referring to specific paragraphs of the MRD, the
         same distinction has been made in this feedback document, i.e. in respectively
         sections 3 and 4.

2.5      The time that was available for the above aviation Stakeholders to provide
         comments was relatively short and will have had a significant effect on the
         completeness of the aviation feedback that is provided. It is proposed therefore,
         that this material be considered as initial aviation feedback, provided to meet
         the GJU GALILEO MRD revision time scales. Further, more complete and
         robust aviation feedback is expected to be provided during the coming
         GALILEO MRD development phases, through a process to be agreed with the
         GJU.

2.6      These reservations notwithstanding, the material presented here is considered
         to provide important initial feedback that is essential for the GJU to take on
         board in the further development of GALILEO. Although some areas of
         comments may need further time to be translated into concrete proposals for
         changes to the MRD, these comments highlight a number of areas where
         concerns exist and where changes may be required to satisfy aviation user
         interests regarding GALILEO.

2.7      In a number of areas studies are ongoing regarding the use of GNSS
         components, including GALILEO, for aviation applications. The outcome of
         these studies, when they become available, may impact the aviation views on
         the requirements indicated in the GALILEO MRD.

2.8      This material has been considered by the members of the EATM ATM/CNS
         Consultancy Group (ACG) as regards its status as aviation community
         feedback. The comments from ACG have been incorporated in this document.



3.                    GENERAL COMMENTS

3.1      This section provides an overview of the comments of a general nature, which
         are not necessarily related to a specific paragraph or section of the MRD. The
         comments are derived from the general comments provided by the aviation
         stakeholders and EUROCONTROL Agency experts. All generic comments that
         have been highlighted by specific stakeholders are provided in Appendix A.

3.2      The overview in this section can not in any way be seen to replace the material
         in Appendix A, but is provided as an indicator of the issues that have been
         raised.

3.3      There is inevitably overlap with the paragraph-specific material that is
         addressed in section 4 and detailed in Appendix B. However, considering the
         relevance of these subjects, this duplication is not thought to detract from the



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         intent of this feedback document and serves to highlight some of the more
         critical issues.

3.4      Some of the feedback calls for clarification of specific requirements or
         statements in the MRD. It is expected that the GJU will provide feedback on
         these issues. Further, some Stakeholders have indicated some editorial
         shortcomings.

The role of GALILEO for aviation

3.5      The aviation community generally accepts that Galileo can offer enormous
         potential to support the extension of GNSS applications in aviation. It would
         provide an essential component of GNSS when the feasibility of “Sole Service
         GNSS”, which could allow the rationalisation of the existing ground navigation
         infrastructure, is considered. It is, however, generally agreed that further work is
         required to investigate how best to use the available GNSS components in all
         phases of flight and to what degree the “sole service concept” can be applied in
         each phase. Moreover the cost-benefit that can be derived from the enhanced
         navigation capability and the rationalisation of the navigation infrastructure must
         be established.

Cost-Benefit aspects

3.6      The cost-effectiveness of the introduction and operation of Galileo is of major
         concern to both aircraft operators and Air Navigation Service Providers. The
         aircraft operators may need to re-equip the aircraft systems in order to fly the
         new GNSS-based applications and the State and/or Air Navigation Service
         Provider usually charge the operator for the provision of the air navigation. As a
         general principle, the operational (and cost-saving) benefits that the GNSS
         based services provide to the aircraft operators should outweigh the cost that is
         born by the aircraft operators for the introduction and operation of those
         services. This would need to take into account the cost of installation and
         certification of additional aircraft equipment. Avionics upgrades are expensive
         and can have a significant impact on any business case.

3.7      While GPS continues to be provided free of charge to aviation users, an
         equivalent level of service would be expected from Galileo on similar terms.
         Where improved accuracy, integrity, continuity and availability are provided, and
         a safety or operational benefit is derived, any charging mechanism should take
         account of the methodology developed by the EUROCONTROL Enlarged
         Committee for Route Charges. Further work on this will be required.

3.8      In this context it needs to be noted that Airspace User Associations have
         indicated that they do not consider the business case material developed by
         Price-Waterhouse-Coopers to satisfactorily cover the relevant cost and benefit
         aspects.

The role of GALILEO in GNSS

3.9      GNSS consists of Basic GNSS, i.e. the satellite constellations such as GPS and
         Galileo (including their modernisation programmes), plus augmentations to
         these constellations such as Space Base Augmentation Systems (SBAS, e.g.
         WAAS, EGNOS, MSAS, GAGAN) and Ground Based Augmentation Systems
         (GBAS).




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3.10     An important aspect that hinders the provision of detailed comments on the
         Galileo MRD is the fact that for aviation, it is unlikely that Galileo will be used as
         the only source for navigation. Galileo is expected to be used in conjunction
         with other GNSS components, such as GPS, and with non-GNSS (at least on-
         board aircraft) navigation sources. Studies into how the various navigation
         sources will support each other are still ongoing. It is therefore difficult in this
         phase to judge the appropriateness of Galileo specific requirements.

3.11     In this sense it is important to note that the degree to which Galileo could be
         used to replace and/or enhance existing navigation infrastructure (ground and
         space based) and the new navigation applications enabled by Galileo, are still
         subject to studies. It may therefore not be appropriate to make reference in the
         MRD to the proposed application but rather to restrict the document to defining
         the Galileo performance requirements.

3.12     In this respect an agreed “concept of operations” for GNSS is required, which
         sets out how the various GNSS components, including GALILEO, will be
         utilised for the various aviation applications. Initial work on this is being
         performed by EUROCAE. Once this work is completed it will still be necessary
         to validate the concepts from an operational standpoint.

The scope of the Galileo MRD

3.13     The MRD needs clarification in respect of the scope of the requirements
         detailed within it. In places it appears to include the receivers while, at other
         times, only the signal in space seems to be addressed. From a certification
         point of view, as the operator of Galileo has no responsibility for the receivers,
         the MRD should restrict itself to the Signal in Space. Where the requirements,
         extracted, inter alia, from ICAO SARPS require an assumption about receiver
         characteristics, these assumptions should be clearly stated. However, the
         requirement should be restricted to the Galileo System itself.

Interoperability GNSS

3.14     It is considered essential for the aviation community that the various GNSS
         components are interoperable, in order to take full advantage of their
         availability. This is particularly the case for GPS and GALILEO, which need to
         be fully interoperable, but independent to the extent that common mode failures
         and degradations are avoided as far as is reasonably practicable.
         Interoperability includes such important aspects as time and geodetic reference
         systems.

Institutional and legal aspects

3.15     GNSS based services should be provided in a proper and agreed institutional
         and legal framework. This is particularly important in those cases where the
         GNSS services are provided by different service (signal and data) providers.

3.16     Furthermore, the international nature of the service and the anticipated global
         use would suggest that consideration of international representation in the
         Galileo management, possibly through ICAO/IMO, would be beneficial.




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Safety of Life (SoL) services

3.17     The added benefits of the GALILEO 'Safety of Life' service is questioned,
         particularly by the aircraft operator community. The 6 seconds Time-to-Alert
         requirement may be difficult and costly to achieve at a global level. The integrity
         of the positioning solution could be assured by RAIM and/or AAIM algorithms
         employed within the airborne systems, and also by augmentation services
         provided by SBAS and GBAS.

Signal Encryption

3.18     The stakeholders feedback also shows significant disquiet with respect to the
         encryption of Galileo signals. Current applications using GPS do not require any
         encryption. A number of stakeholders have expressed serious reservations that
         encryption will reduce availability significantly with no appreciable gains in any
         other areas. Moreover, the use of encryption would be contrary to long-
         established aviation practice with respect to the use of navigation aids.

Authentication

3.19     The stakeholder feedback also shows concern about the real advantages to be
         provided by signal signature. There are differing views on the use of
         authentication. Two States see benefits from an anti-spoofing capability while
         others are concerned that it will lead to increased receiver complexity and
         reduced end-to-end availability. A number of stakeholders have highlighted the
         need to be able to use the signal even if the signal signature is not validated.

3.20     The need for the proposed authentication has still to be fully justified. The
         Galileo signal is very difficult to spoof and, using GPS and other (e.g. Inertial)
         data, there may be sufficient on-board means of validating the position derived
         from Galileo. The above, together with the acceptance (over many years) of
         signals which have no means of validating the authenticity for flight critical
         applications, leads many to question the need for Authentication.

3.21     Additionally there is a requirement that the data still be available for use even if
         authentication fails.



4.                    SPECIFIC COMMENTS ON THE GALILEO MRD VERSION 5.3
Introduction

4.1      This section provides a brief synthesis of the aviation community feedback that
         was provided on specific sections and paragraphs of the Galileo MRD V5.3.
         The complete feedback is detailed in Appendix B to this document.

4.2      The overview in this section can not in any way be seen to replace the material
         in Appendix B, but is provided as an indicator of the issues that have been
         raised. Nor is the inclusion of material in this section intended to be based on a
         prioritisation, since all material in Appendix B is considered to be important to
         be taken into account in next versions of the GALILEO MRD.

4.3      Although some of the feedback refers to more than on paragraph of the MRD, it
         is endeavoured in this section to provide an indication of where the issue is



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         dealt with in the MRD, for reasons of traceability. However, the feedback may
         be associated with more paragraphs than those indicated.

Timescales (§2.1.3)

4.4      The timescales are not precise and the feasibility of those provided are
         questioned.

Legal and Service Guarantees (§1.11)

4.5      These are not yet elaborated in this version although they are of vital
         importance. The aviation community should have early access to the text
         concerning Legal and Service Guarantees Related Issues, the section on
         Justification, the Legal Annex and all referenced documents.

Interoperability with GPS (§2.4)

4.6      The issues raised in the replies concern a number of issues related to
         interoperability with GPS. It is considered critical that such interoperability
         exists.

4.7      Specific issues include:

         •    Commonality of frequencies, signal structure, time reference etc (e.g. §2.2).

         •    The use of a single terrestrial reference frame (e.g. §2.4.2). It is not
              understood why GTRF is to be adopted (and presumably maintained) when
              ITRF in which the GPS control stations are now referenced, is available.
              The European component - ETRF is available and maintained as a
              reference frame through EUREF.

Open Service (§1.1 and §3.2.1)

4.8      The Open Service should be at least the equivalent of GPS in terms of
         performance with access free of cost.

Service Coverage (§1.1 and §3.1.4)

4.9      The performance of the Global Service should be equivalent worldwide and not
         require additional regional or local components in certain areas in order to
         achieve the same performance provided by the Global service elsewhere.

System Performance (e.g. §3.1)

4.10     The accuracy estimation must take account of all error sources and must not be
         limited to clock and ephemeris errors. In this context, “worst case” assumptions
         should be used (§2.6.2 and §3.1.3).

4.11     The specification of the level of performance with respect to interference must
         be more detailed. The existing ICAO mask for L1 is not sufficient and specific
         masks should be defined for the E5 band as well. (§3.2.2.5)

4.12     The performance specification for precision approaches, particularly Cat II/III,
         must follow the standards that are currently being developed by ICAO. (e.g.
         §3.4.2)


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Safety of Life Service (§1.1 and §3.2.2)


4.13     There are differing views on the need for a safety of life service. With multiple
         sources of data, including GPS, many of the validation requirements for aviation
         applications can be made without this service. If it is provided, a number of
         issues arise:
         •    There are differing views on whether 6 seconds TTA is acceptable for Cat I
              precision approach applications as stated – if this figure includes all delays
              up to the pilots display, then this needs to be stated and the assumptions
              made about receiver and display latency must be provided.

         •    There are differing views on the lack of provision of integrity information on
              E5a - one State proposes removing E5a from the aviation receiver
              specification while others make a strong case for the inclusion of the
              integrity information on both E5a as well as E5b. There is an advantage in
              providing integrity on E5a as it will improve compatibility with GPS. If E5a
              carries the integrity information then the aviation community would not
              require E5b. The removal of E5b could ease the compatibility with DME
              since clearing both E5a and E5b will not be possible if it is found the DME
              interference is unacceptable. If it is considered of interest to change the
              signal specification in relation to E5a and E5b, further discussions would be
              required to decide the optimum way forward.
Availability & Integrity (§3.2.1.1, §3.2.1.2, §3.2.2.7 - §3.2.2.10,)

4.14     Whilst global availability is quoted as a percentage, no maximum outage
         duration is identified. It has been proposed that a maximum outage of 35
         minutes in any day is specified (i.e. twice the global average). The associated
         integrity requirements as currently specified are questioned.

Dynamic Performance (§3.2.1.1 and §3.2.2.4)

4.15     The User Dynamic Conditions for Level A and B are not wholly compatible with
         aviation requirements. Aircraft speeds can easily exceed those stipulated for
         both Levels, as can bank (roll) and pitch angles.

Time to Fix (§3.2.1.3)

4.16     Time to first fix and reacquisition time needs to be defined in more detail.

GALILEO and “Sole Service GNSS” (remark in §3.3)

4.17     The MRD should not make a case for GALILEO enabling “Sole Service” without
         satisfactory supporting material. Stakeholders have indicated that it is not
         considered appropriate to make these claims before the required studies have
         been performed.

Lifetime (4.3.1)

4.18     A 20 year lifetime is exceedingly short for aviation planning. A cost effective
         transition from one navigation system to another would normally take at least 20
         years. The risk of a loss of service before a complete transition occurs would
         remove any incentive to commence the transition. A guarantee of at least 40 to
         50 years would probably be needed.


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5.                    CONCLUDING REMARKS


5.1      It should be recognised that the time scales available for developing the
         feedback in this document were very tight. Therefore the feedback provided is
         not necessarily complete, and further feedback is expected to materialise after
         this consultation phase. EUROCONTROL is in consultation with the GJU to
         determine how this further feedback will be accommodated. However this
         material is considered to provide important user feedback, addressing aspects
         that are of specific concern to the potential aviation users of GALILEO and, as
         such, should be carefully considered by the GJU in the next version of the MRD
         and during the further GALILEO development phases.

5.2      The requirements on Galileo to support aviation applications are very
         dependent on the individual applications, and are also dependent on the
         availability of other navigational aids (e.g. other GNSS components) that aircraft
         systems can use to derive integrated navigational solutions. Studies are
         ongoing on these subjects and relevant results will be made available to the
         GJU in support of the development of GALILEO.

5.3      The aviation community is considered a relatively small user of GALILEO,
         taking into account the wide application area that is foreseen. Although
         GALILEO is expected to provide important benefits to aviation, these benefits
         still need to be validated and quantified. This is a pre-requisite for any
         consideration of cost allocation for GALILEO based services, which may be
         supported by other GNSS components and non-GNSS navigation means.

5.4      All feedback provided in this document is considered relevant for the GJU to
         take into account in developing the next version of the GALILEO MRD. Some
         issues have been highlighted by many Stakeholders, such as the need for the
         Safety-of-Life service, authentication and encryption. All areas indicated may
         warrant amendments to the GALILEO MRD.




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                                                            APPENDIX A
                                               GENERAL COMMENTS ON THE GALILEO MRD V5.3

                       (Where a contributor has identified a comment as being of major importance, it is highlighted in bold)

                                                                 Comment                                                                 Contributor
 A global integrity service such as that which has been proposed for Galileo could pose liability problems which do not appear to        AENA
 have been evaluated.
 From a technical point of view, the provision of integrity at global level may represent some compliance difficulties with stringent
 performance requirements (e.g., 6 seconds as time to alarm).
 The provision of integrity on a regional or global basis has to consider all the factors before taking a final decision.
 If the performance of the Galileo Global Services (Global Component) is to be equal in the defined service area, this must mean         AVINOR
 that that, throughout the EUR region, there will not be any need for additional Regional and/or Local components to achieve the
 minimum performance. .
 More involvement of military partners should be appreciated.                                                                            Belgocontrol
 As an Air Navigation Service Provider, DFS Deutsche Flug Sicherung is committed to exploit the benefits which can be obtained           DFS
 from GNSS in order to improve the quality of service to our customers.
 Galileo, in conjunction with GPS and its augmentations, offers the potential for increased accuracy and robustness of GNSS.
 Additionally we value the fact that Galileo is conceived as a satellite constellation under civil control, independent from GPS and
 interoperable with it.
 Requirements from the Air Navigation Service Providers are given based on performance requirements for navigation systems as            DFS
 derived by ICAO. It is not clear at the present time, how the characteristics of the planned navigation service will be quantified as
 benefits for the aviation user.
 While the world wide benefits of Satellite based Navigation Systems are indisputable, the intensive amount of effort that has been      ERA
 expended thus far has failed to produce an acceptable solution for low visibility approaches.
 Current Navigation systems (e.g. ILS/MLS) are required and should be maintained for the foreseeable future, or until viable
 alternatives are commonplace.
 Some regional operators have reported that the current satellite system signal is sub noise threshold and is vulnerable to
 intervention - either deliberately or by the environment - particularly so during approaches.
 Some aircraft currently in production have DME/DME RNAV systems and certain regional types still rely on NDB/ADF for certain




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                                                                  Comment                                                                        Contributor
 approaches.
 Satellite systems are very expensive and cannot be maintained by Industry. This has to be Government funded now and in the
 future. The current demise of Hubble for want of some cash is a clear case in point.
 GNSS could/should not yet become the sole means of navigation as this has not yet been proven from a technical, safety and
 cost/benefit point of view.
 Airlines are not interested in technology for the sake of technology. GNSS is just one enabling technology which could potentially
 be used for new operational applications.
 The current Galileo Business case study is open to question.
 The airspace users are, in the present ANSP 100% cost recovery situation, strongly opposed to such providers joining the Galileo
 PPP initiative, since ATS Providers do not take any commercial ‘risk’ and therefore cannot been seen as private investors.
 Transition costs (retrofit of in-service aircraft, particularly to the regional fleet) are also potentially very high, and this must be taken
 into account in any business case.
 Although broad support for future GNSS activities may be desirable, a more robust case should be made in regards to funding, to
 ensure that aviation does not pay a disproportionate amount of the costs compared to other potential users of such systems.
 From the user perspective, an assessment of any GNSS cannot relate to the space segment only. The receiver needs to be seen                     IFALPA
 as an integral and important part of the total system. Only an end-to-end functional assessment including the receiver is
 acceptable to IFALPA / ECA. This perspective appears to be in need of better emphasis.
 Any GNSS should be under the jurisdiction and control of an international civil organisation.
 Any GNSS should only be commissioned for full use, in particular as a precision approach aid, after the following are assured:
         -       the availability of sufficient satellites, including spares in orbit
         -       non-interruption of service, and
         -       non-degradation of service
 Any GNSS should offer, for all approved types of use (e.g. oceanic, en-route, terminal or approach navigation), at least the same
 levels of safety, integrity, reliability and availability that are presently required from terrestrial navigation systems.
 Specifically, requirements for system inherent failure tolerance and reliable failure detection and warning mechanisms include:
 a)      failure of one or even several satellites at any one time should not significantly degrade the system performance.
 b)      timely detection of satellite failures and transmission of related status messages should be provided by the GNSS, so as to
 enable:
 i)      automatic deselection of faulty satellites by the receiver when defined criteria are exceeded;



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                                                                  Comment                                                              Contributor
 ii)     generation of failure warnings in case of degraded system operation, and
 iii)    indication to the pilot and ATS of system degradation predictions with reference to time and geographical location, thereby
 allowing planning of alternative actions.
 c)      reliable detection of an unannounced failure of one or several satellites within the airborne receiver; the faulty satellite
 should be automatically deselected when defined failure criteria are exceeded.
 Information about the present and predicted status of the GNSS should be readily available at the time of flight planning and
 during all phases of flight.
 Legal responsibility for continuity, reliability and quality of GNSS service should be clearly defined.
 The MRD in its current form contains serious issues for Civil Aviation that need to be addressed before we are in a                   NATS UK
 position to give the system our full endorsement.
 As an Air Navigation Service Provider, NATS is committed to exploit the benefits, which can be obtained from GNSS in order to
 improve the quality of service to our customers. Galileo, in conjunction with GPS and its augmentations, offers the potential for
 increased accuracy and robustness of GNSS. Additionally we value the fact that Galileo is conceived as a satellite constellation
 under civil control, independent from GPS and interoperable with it, but would urge that our concerns are fully and completely
 considered before full endorsement can be given.
 Requirements from the Air Navigation Service Providers are given based on performance requirements for navigation systems as
 derived by ICAO. It is not clear at the present time, how the characteristics of the planned navigation service will be quantified as
 benefits for the aviation user.
 There are many implications on institutional aspects within the MRD, which need to be well understood. These impact on legal,
 financial, certification, cost recovery and operational issues and also impact the terms of some ATSPs operating license. These
 need to be explored in greater detail then this technical evaluation could perform. It is recommended that this is discussed by a
 group of experts containing the following expertise:
 a)      Engineers (ATSP’s)
 b)      Safety Regulators (CAA’s) – (both air and ATC regulators)
 c)      Economic Regulators (CAA’s),
 d)      Legal (ATSP & CAA’s), and
 c)      Financial (ATSP)
 The civil aviation community considers that authentication could be acceptable on the assumptions that the use of it is
 optional and that the data throughput required for it is acceptably low with regards to the associated reduction of




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                                                                   Comment                                                                Contributor
 robustness to interference and that the key management issue can be safely managed, however the encryption of the
 ranging code for security reasons has proven to be unacceptable.
 The reduction in security level induced by the user transparent feature required is such that it is worthless to implement
 ranging code encryption for security reasons. (In fact a security board meeting in November 2003 stated that the reason
 they included encryption in there requirements was because they had been told it was an aviation requirement – so this
 loop needs breaking. It should be stated that the encryption of all or part of the navigation data brings no security
 advantage.
 Encrypting the SIS for commercial reasons could lead the civil aviation community not being able to use the encrypted
 Galileo SISs as it would then be discretionary on whether the user pays or not. This would mean ATSP’s would need to
 continue to provide a “legacy” service for those users who choose not to pay to the GOC. Therefore it is a major concern
 that either OS, SoL or both be encrypted in part or totally.
 The need for external integrity regions is questionable. This is not a civil aviation community requirement. This feature leads to
 increase the data rate required to transmit integrity information thus reduces robustness and increases TTF in reacquisition mode
 which is increasing the impact of the interference threat.
 In addition the direct uplink capability that is offered in this scheme has safety and security impacts that have not been assessed.
 Another issue is the transmission of the applicability area through SIS. This supposes that all modes of transport will rely on the
 same geographical partitions, which may not be the case. The transmission of this information also increases the navigation data
 rate.
 There are no details on how the security requirements impact or need to be considered by certification agencies. To gain
 acceptability a procedure needs to be created that will give certification authorities understanding of the security requirements in
 order to allow them to assess the compatibility with safety regulations and certification requirements.
 The fault-free receiver concept seems to be misused in some occasions. There is a tendency to confuse a fault-free receiver with
 a perfect receiver. A fault-free receiver should be used only to derive requirements from pseudo-range level to position level. Any
 receiver, fault-free or not, will need some computation time which needs to be taken into account in the TTA allocation.
 References to existing standards, which are applicable to GPS L1, are not appropriate for Galileo. There will be new standards
 produced for Galileo and GPS L5. Therefore references to ICAO SARP and receiver MOPS are not pertinent outside of GPS L1
 environment.
 There is no requirement concerning maximum outage duration. The availability requirements are expressed in such a way that an
 outage of 15days would still be compliant with the MRD, where as this is obviously not acceptable. A way to solve this issue would
 be to have a maximum outage duration requirement.




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                                                              Comment                                                                     Contributor
 The use of pseudolites is detailed. However pseudolites will need a ground to air allocation. They cannot currently be used in the
 GNSS bands as these are space to ground allocations. This needs addressing at ITU.
 Requirement for SIS in ICAO SARP are considered for a single aircraft performing a specific operation. These                             STNA
 requirements are not directly applicable at system level where SIS is used in many simultaneous applications for many
 different aircraft in many different areas all over the world. This MRD instead applies directly single aircraft requirement
 as system requirements. The assumptions underlying to this approximation should be clarified.
 The MRD contains serious issues for Civil Aviation that need to be addressed and much more consultation is required to                   UK CAA
 explore them in greater detail than the technical evaluation could allow. The timeframe for this consultation was much
 too short and should be continued in suitable for a to include all interested parties.
 The issue of how the Galileo Operating Company is set up must be addressed since this will impact on how the civil aviation
 community conducts its business. Therefore legal and economic regulators must be included in the consultation process.
 There is general concern as to how the consultation process is being managed and whether or not the views of the aviation
 community will be adequately represented at the higher levels.
 The document has been written using a very old version of the Signal in Space ICD. As the present negotiated signal structure is
 radically different from that assumed in this document detailed assessment of it is difficult. The document needs to be re-written
 using the signal structure negotiated with the US.
 Galileo should be a purely civil system and any proposals to develop military features, or those that impacted adversely upon
 defence capabilities, would be resisted.
 Galileo should be interoperable and compatible with GPS but must not affect military applications of the system. We are
 concerned that the proposed Public Regulated Service (PRS) may do this. The PRS should be used for civilian purposes only
 and must be properly controlled. We believe that the proposed high level of encryption arguably goes beyond what is necessary
 for civil use.
 We understand that the current proposal is for the primary PRS signal to overlay the planned GPS M-code signal. This has the
 potential to jeopardise the military effectiveness of NATO and US-led coalition operations. This is unacceptable and we would
 wish continued lobbying within the EU for alternatives to be pursued. Some NATO nations have indicated that they do not wish to
 rule out a military use of PRS. We would resist this as PRS would duplicate what is currently available to European military
 forces. GPS is the de facto military standard and should remain so.
                                                                   Table 1 - General Comments




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                                                           APPENDIX B
                                     COMMENTS ON SPECIFIC PARAGRAPHS OF THE GALILEO MRD V5.3

                                 (Where a contributor has identified a comment as being of major importance, it is highlighted in bold)


Paragraph                                        Text                                                                   Comment                      Contributor
    No
1.1            Galileo’s mission is to provide users with a state-of-the-art high                Aviation is interested in a Global improvement      NATS UK
               accuracy global positioning and timing capability. This global                    that would allow decommissioning of the
               capability will be designed to meet the needs of a wide range of                  legacy navigation infrastructure on a on a
               applications in multi-modal transport domains.                                    global scale. Galileo therefore should be open
                                                                                                 to international Participation - possibly
                                                                                                 through ICAO/IMO.
1.1            Galileo is a civil system, operated under public control. Its missions            Does this mean European Military Forces             NATS UK
               include:                                                                          must continue to rely on GPS for their
               Implementing an independent Global Navigation Satellite System                    positioning service?
               (GNSS) that will fit in with and operate alongside existing and
               planned navigation and communication systems to provide both
               enhancements and redundancy;
               Improving the European infrastructure, particularly for multi-modal
               transport, while providing a global high-quality civil Position-
               Velocity-Time (PVT) capability;
               Supporting the special needs of safety of life and other applications
               and anticipating the needs of value-added suppliers in creating new
               markets and applications;

1.1            To a large extent, these mission requirements have been formally                  Integrity and authentication are mandatory for      Belgocontrol
               expressed in terms of the services that Galileo will make available               civil aviation. Both capabilities will be part of
               or will support. These services are planned to include:                           the SoL (Safety of life) service but will an
               An Open Service (OS) - providing positioning, navigation and                      encryption capability be available as well?
               timing services, free of charge, for mass market navigation
               applications and competitive to the GPS Standard Positioning                      Authentication of service, and or lack of it
               Service and its evolutions;                                                                                                           NATS UK
                                                                                                 needs to be reviewed from an operational



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Paragraph                                         Text                                                            Comment                        Contributor
   No
               A Safety of Life Service (SoL) – compliant to different standards in          aspect. The idea seems sound, however what
               the aeronautical, maritime and rail domains. The SoL includes                 are the operational procedures if a signal is
               Integrity and Authentication capabilities. The SoL include service            use which can not be authenticated and how
               guarantees;                                                                   are authentication key management to be
               A Commercial Service (CS) - generates commercial revenue by                   implemented in an international safety of life
               providing added value over the Open Service, such as by                       environment?
               dissemination of encrypted navigation related data (0.5 kbps),
               ranging and timing for professional use - with service guarantees;            OS competitive to GPS SPS. It should be
               A Public Regulated Service (PRS) - for applications devoted to                indicated what is the baseline for comparison       STNA
               European/National security, regulated or critical applications and            : actual GPS or modernised GPS.
               activities of strategic importance. The PRS will provide robust and
               encrypted signals, under Member States control;A Search and
               Rescue Support Service (SAR) - provides assistance to the
               COSPAS-SARSAT system by detecting Emergency Beacons and
               forwarding Return Link Messages to the Emergency Beacons.

1.2            GALILEO GLOBAL COMPONENT                                                      It is surprising that Galileo reference receivers   AENA
               The Galileo global Component contains all the necessary                       are part of the Galileo Global component.
               infrastructure elements to provide the Galileo Satellite-only                 This requires a clarification within the
               Services. It comprises a constellation of satellites in Medium Earth          document.
               Orbit (MEO) ,its associated ground segment and the Galileo
               reference receivers. It is under the control and the responsibility of
               the Galileo operator (Galileo Operating Company).




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Paragraph                                          Text                                                            Comment                     Contributor
    No
1.3             REGIONAL COMPONENTS                                                           EGNOS will be used to deploy Galileo             Belgocontrol
                Over the European Region, the combination of the Galileo satellite-           regional components within Europe. But will it
                only services with the EGNOS services will allow achieving higher             be possible to deploy similar components
                standards of navigation performances, especially for the safety of            outside Europe (in North and South America
                life applications.                                                            or Asia for example)?
                                                                                              What about polar regions (EGNOS, WAAS
                                                                                              and/or MSAS do not cover polar regions)?
                                                                                              Civil aviation needs indeed a world-wide
                                                                                              approach, not one that is only valid for
                                                                                              Europe.

1.3             REGIONAL COMPONENTS                                                           The operational aspects of integrity provided    NATS UK
                Furthermore, the so-called regional integrity components will                 by different regions under different regional
                provide the possibility for regions to determine and uplink their own         law will have to be assessed leading to an
                integrity flags either by means of dedicated regional integrity uplink        ICAO standard on the application of
                stations or via a respective interface and the Galileo uplink stations.       regional/global components of the Galileo
                This concept will allow regions to use Galileo as navigation means            system.
                for regulated, mostly safety-of-life related applications. The regional
                infrastructure is under the sole responsibility of the region itself.         Dedicated regional integrity uplinks may         STNA
                                                                                              present an unacceptable safety and security
                                                                                              risk.
1.7             Applicability of Galileo Mission Requirements Document                        Please, replace SRD’s by ICD’s when              AENA
                The Mission Requirements specified in this document are                       referring to the ‘Galileo Service and Signal
                applicable to the elaboration of the Galileo System Requirements              Interface Control Document’.
                Document (SRD) and to the Galileo Service and Signal Interface
                Control Documents (SRD’s).
                The requirements in this document shall supersede the lower level
                requirements in case of conflict.

1.11            LEGAL AND SERVICE GUARANTEES RELATED ISSUES.                                  The section on ‘Legal and Service                AENA
                The MRD is primarily a high-level technical requirements                      Guarantees Related Issues’ points to Annex


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Paragraph                                           Text                                                            Comment                       Contributor
   No
                 document. However, there are many requirements, in particular                 1, which is still missing. We believe such
                 with respect to the service guarantees and availability, which have           important topics should be elaborated in the
                 implications with respect to management, institutional and legal              main body of the MRD and not in an Annex.
                 matters. All such topics will form part of Annex 1 of the MRD..               Anyhow, the material is still pending and
                                                                                               should be included in the MRD asap

                                                                                                                                                  UK CAA
                                                                                               Annex 1 is not included and therefore
                                                                                               balanced comment is not possible. Indeed
                                                                                               the ‘Applicable Documents’ referred to in
                                                                                               section 1.13 should also be made available
                                                                                               so that the issues for civil aviation can be
                                                                                               properly addressed.
1.13             APPLICABLE DOCUMENTS                                                          These documents are defined as applicable.         NATS UK
                                                                                               Therefore they are required for an efficient
                                                                                               and effective reveiw of this MRD. ( For
                                                                                               example, some of the requirements such as
                                                                                               TTF can not be justified without
                                                                                               complimentary information on the signals and
                                                                                               the message as it involves allocation of
                                                                                               system parameters between signal and user
                                                                                               terminal - this would/should be in AD6).
1.15             JUSTIFICATION FILE                                                            Need to see this document to determine how         NATS UK
                                                                                               (and correctness) the specifications in this
                                                                                               document Have been determined.
2.1.3            Operational Service Date                                                      By 2008 implies end of 2007 at the latest.         NATS UK
                 The Galileo Global component shall be fully operational with                  Perhaps "during 2008" is what is meant. As it
                 service availability by 2008.                                                 is a requirement document we should really
                 Remark : The calendar of the certification process is TBD                     express this as follows: "...by end of 2008", or
                                                                                               "....by 31st December 2008".

                                                                                               The envisaged operational service date, ‘by
                                                                                               2008’ is misleading since a) it is not a precise   AENA


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Paragraph                                           Text                                                            Comment                        Contributor
   No
                                                                                               date, i.e. is it January or December 2008?
                                                                                               and b) the text refers to a ‘fully operational’
                                                                                               service which can be understood as being
                                                                                               both technically and operationally validated so
                                                                                               as to be usable by multi-modal end-users.
                                                                                               However, the remark points out that the
                                                                                               calendar for the certification process is TBD.
                                                                                               Please, clarify.
                                                                                               In addition, today (March 2004) it seems to be
                                                                                               unrealistic, as development phase has started
                                                                                               with a lot of delay.

                                                                                               A more precise and realistic date should be         STNA
                                                                                               given
2.2.1            Galileo – A European Controlled System                                        For international civil aviation it may be better   NATS UK
                 The Galileo Global component shall be controlled by a European                to say: "...by a European Entity with
                 entity.                                                                       international participation".

                                                                                               It seems that with a regional integrity             STNA
                                                                                               direct uplink the control over the global
                                                                                               component becomes only partial.
2.2.3            Galileo - Terrestrial Reference Frame Autonomy                                What can be expected from the new                   Swiss
                 The Galileo Terrestrial Reference Frame (GTRF) shall be                       reference frame GTRF? Despite some                  Federal
                 established autonomously from other terrestrial reference frames.             deficiencies of the WGS84 it has to be              Office for
                                                                                               recognised that ICAO uses WGS84 as the              Civil Aviation
                                                                                               reference frame for aviation. If GTRF is used
                                                                                               for Galileo then precise transformation
                                                                                               parameters have to be defined, which may
                                                                                               cause some problems and result in position
                                                                                               errors. Furthermore a mix of the two
                                                                                               reference frames WGS84 and GTRF is an
                                                                                               error source when not used properly (


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Paragraph                                             Text                                                            Comment                      Contributor
   No
                                                                                                 integrity issue).
2.3.2              Galileo Filings Protection                                                    The Galileo MRD is dated October 10, 2003,        Belgocontrol
                   Galileo satellite deployment shall ensure a successful declaration            but mentions that the declaration of the L1
                   of its “entry into use” before June 2006 for L1 frequency and                 frequency band entry into use has to be done
                   December 2006 for E5a, E5b and E6 frequencies, including any                  before June 2003. Change the date or use
                   possible launch failure.                                                      the past tense.
                   Remark: In L1 frequency band, the declaration of its enter into use
                   has to be done before June 2003, with an automatic extension of 3
                   years if requested (June 2006). In the other band (E5, E6), the
                   declaration of their enter into use has to be done before December
                   2004, with a possible extension of two years if requested and
                   justified, i.e. extension up to December 2006.



2.4                INTEROPERABILITY                                                              Some airlines interviewed would like Galileo      NATS UK
                                                                                                 to be interoperable with GPS using the same
                                                                                                 frequencies and signal format. This is a
                                                                                                 different approach to the one considered in
                                                                                                 this document.
2.4.1.1            Interoperability with GPS SPS Service and GLONASS SPS Service                 Does not speak to the absolutely critical need    IFALPA
                   The Galileo Global component shall facilitate the combined use of             for the user equipment to seamlessly make
                   Galileo Open Service and Safety of Life services with the GPS                 use of GPS, GLONASS and Galileo without
                   Standard Positioning Service and its evolutions and with the                  user intervention. To facilitate the combined
                   GLONASS SPS Service and its evolutions.                                       use of various GNSSs is not sufficient.

                                                                                                 The compliance to a facilitation requirement is
                                                                                                 difficult to verify.                              STNA
2.4.1.2            Compatibility with GPS Services and GLONASS Services                          Again, non-harmful interference basis is short    IFALPA
                   The Galileo services shall be able to operate on non-harmful                  of the user expectation to seamless
                   interference basis with the GPS services and with the GLONASS                 operations using the various GNSS.
                   services.


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Paragraph                                             Text                                                            Comment                     Contributor
   No

2.4.2              Terrestrial and Time Reference Frames                                         While this may be acceptable from an             EUROCONT
                   Terrestrial Reference Frame Compatibility                                     operational point of view, it is not clear why   ROL
                   The Galileo Terrestrial Reference Frame (GTRF) shall be                       GTRF has been chosen in place of ITRF.
                   compatible with the International Terrestrial Reference System                The cost of maintaining a separate reference
                   (ITRS).                                                                       frame does not seem to be justified in any
                                                                                                 additional benefits.
2.4.2.7            Galileo/GPS Time Offset Broadcast                                             This specification should be hardened. By        NATS UK
                   The offset between Galileo System Time and GPS System Time                    using "feasible and appropriate" the
                   shall be broadcast to the users in all Galileo Signals where feasible         specifications is weakened. Would prefer to
                   and appropriate.                                                              see ".....shall be broadcast to the users via
                                                                                                 each channel of each signal in space."

                                                                                                 What does feasible and appropriate mean
                                                                                                 with regards to the difference between GST       STNA
                                                                                                 and GPS ST ? This requirement is very easy
                                                                                                 to comply with.
2.5                Security                                                                      Concerning the security requirements,            STNA
                   The Galileo security requirements are defined in the Applicable               there is no means through this MRD to
                   documents AD 3 to AD 5.                                                       comment on the implications wrt safety,
                                                                                                 acceptability and certifiability of the
                                                                                                 system. A mechanism has to be set up to
                                                                                                 give certification authorities insight on
                                                                                                 security requirements for them to assess
                                                                                                 compatibility with safety regulations and




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Paragraph                                                   Text                                                                       Comment                                   Contributor
   No
                                                                                                               certification requirements.
2.6.1            User Level Mission Requirements                                                               To assess performance requirements using                         IFALPA
                 The performance requirements shall be fulfilled at user level,                                typical navigation performance by a reference
                 including the receiver contribution, unless otherwise specified.                              receiver in reference environmental
                 Remark: Typical navigation performances (accuracy, integrity,                                 conditions falls short of the IFALPA / ECA
                 continuity and availability), are defined for each type of service (OS,                       requirement that navigation performance be
                 SoL, CS, PRS) ,, under the condition, that a user is:                                         always monitored and assessed under actual
                                                                                                               encountered conditions.
                        - 1) using a reference receiver1;
                        - 2) operating in reference environmental conditions and                               Here it is said the requirements include                         NATS UK
                 users dynamic conditions.                                                                     receiver contribution while later on it gives
                                                                                                               requirements in terms of the "fault free
                                                                                                               receiver", i.e. not including receiver
                                                                                                               contributions. This needs to be clarified. In
                                                                                                               fact one needs to read note (1) to realise that
                                                                                                               the requirements in this document do NOT
                                                                                                               include receiver performance. Needs some
                                                                                                               tidying up here.

                                                                                                               The fault-free receiver concept seems to                         STNA
                                                                                                               be misused in some occasions.
                                                                                                               Apparently there is a tendency to confuse
                                                                                                               a fault-free receiver with a perfect receiver.
                                                                                                               A fault-free receiver should be used only
                                                                                                               to derive requirements from pseudo-range
                                                                                                               level to position level. Any receiver, fault-
                                                                                                               free or not, will need some computation
                                                                                                               time taken into account in the TTA for
                                                                                                               example.

        1
         Reference receiver and environmental conditions are currently being defined by the appropriate fora (ICAO, IMO…). Pending these results the typical navigation performances are
        defined using the fault-free receiver.



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Paragraph                                             Text                                                            Comment                       Contributor
     No
2.6.2.1.5          Archive Information                                                           Duration of archiving should be compatible         STNA
                   The Galileo Global Component shall have the capability to receive             with accident investigation requirements.
                   requests for, and provide all archive information related to the
                   Galileo satellite-only services.
2.7.1              Signal In Space (SIS) Standardisation                                         If it is decided to encrypt the data, which        NATS UK
                   The SIS description shall be in the public domain for the Open,               forms part of the SIS ICAO characteristics,
                   Commercial, SoL and SAR services as the basis of the SIS                      then how will it be possible to have the total
                   standardisation process.                                                      SIS in the public domain?
                   Remark: The SIS description will be made available through the
                   SIS Interface Control Document.

2.7.2/3            Certification scheme                                                          FALPA / ECA fully and strongly support the         IFALPA
                   A certification scheme shall be implemented that covers both the              establishment of a certification scheme, and
                   validation of Galileo signals in space against the SRD requirements           certification implementation through an
                   and the Galileo services against the present MRD requirements.                independent and impartial certification body.
                   Certification authority                                                       Certification should be based on an end-to-
                                                                                                 end (total system) performance evaluation.
                   The certification shall be achieved through the implementation of
                   an independent and impartial certification body.
                                                                                                 Is it expected that if a new certification         Swiss
                   Remark: The certification body will perform evaluations, audits,                                                                 Federal
                   verification and inspections covering system design, development,             authority is set up for Galileo, that this
                                                                                                 authority will have to work with the               Office for
                   validation and operations, as well as personnel qualification and will                                                           Civil Aviation
                   deliver statements of conformity to identified standards and other            established authorities for aviation in order to
                   normative documents.                                                          obtain certification for aviation use.
2.7.4              Standard Modification Notice Any change to Galileo SIS                        7 years minimum notice is normal within the        EUROCONT
                   standards that is not backward compatible shall be notified to users          aviation community                                 ROL
                   with 6 years advance warning, at a minimum.
                                                                                                 Should a change to the Galileo SIS (signal in      Belgocontrol
                                                                                                 space) standards be planned that is not
                                                                                                 backward compatible, a 6 year warning delay
                                                                                                 is not enough for civil aviation.



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Paragraph                                         Text                                                            Comment                     Contributor
   No

                                                                                             Is 6 years not too short a time if it means      NATS UK
                                                                                             replacing equipment in aircraft. The airline
                                                                                             community would like a longer period than
                                                                                             this. ICAO normally requires 7 years. The 6
                                                                                             years comes from GPS congressional funding
                                                                                             constraints, which Europe need not be bound
                                                                                             to. We should avoid changing the SIS if we
                                                                                             can and probably 15 years is a minimum the
                                                                                             airlines would feel happy with.
3.0            Galileo Services Requirements                                                 In the introductory note to Chapter 3, it is     Belgocontrol
               Introductory note to Chapter 3:                                               mentioned that EGNOS services will be
               The definition of the Galileo services is based on a comprehensive            combined with Galileo satellite-only services.
               review of user needs and market analysis. There will be some                  Such combined services won’t be available
               services provided autonomously by Galileo and other services                  outside Europe because EGNOS does not
               resulting from the combined use of Galileo with other systems. This           cover the whole world.
               leads to the classification of the Galileo services into four                 Are there plans to facilitate the extension of
               categories:                                                                   these combined services to WAAS and MSAS
               Galileo satellite-only services                                               or at least to make them compatible through
                                                                                             standardisation?
               These services will be provided worldwide and independently of
               other systems using various combinations of the signals broadcast
               by the Galileo satellites. There is a wide range of possible
               applications with different operational requirements that have been
               grouped around the following five reference services:
                       Galileo Open Service (OS)
                       Safety of Life (SoL).
                       Commercial Service (CS).
                       Public Regulated Service (PRS).
                       Support to the Search and Rescue service (SAR).
               Galileo-satellite only and EGNOS combined services
               EGNOS will provide an augmentation to GPS and GLONASS


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Paragraph                                           Text                                                            Comment                     Contributor
   No
                 services, over Europe, from 2004 onwards. This service will allow
                 for early experience in the development of “Galileo-type”
                 applications. The EGNOS services will be combined with the
                 Galileo satellite-only services. This will allow higher performance
                 levels to be met by using different sources of integrity and
                 navigation information. The EGNOS services are specified in the
                 related EGNOS MRD [RD5].
                 Galileo Locally Enhanced Services
                 The Galileo satellite-only services can be enhanced on a local
                 basis through a combination with local elements. The result will be
                 the provision of local services.
                 Galileo Combined Services
                 All the above-mentioned services can be combined with services
                 provided by other navigation or non-navigational or communication
                 systems. This possibility will improve the GNSS service availability
                 at user level and open the door to a wide range of applications. The
                 result will be the provision of combined services.
3.1.3            Default Operational Conditions                                                Interference environment is defined for every    AENA
                 Unless otherwise specified for a particular service, the default              signal (frequency) in SARPs. It is
                 operational conditions shall have:                                            recommended to include the word 'equivalent'
                 No intentional jamming;                                                       within this requirement.
                 A defined interference environment no better than those defined in            Multipath user environment: it is
                 ICAO GNSS-P SARPS;                                                            recommended to include a clear reference to
                                                                                               any existing document.
                 Low multipath user environment, as defined in GNSS MOPS;
                 No denial of services;                                                                                                         Belgocontrol
                                                                                               The default operational conditions shall have
                 No shadowing;
                                                                                               a defined interference environment ‘no worse’
                 Mild ionospheric conditions                                                   (instead of ‘no better’) than those defined in
                 Mild tropospheric conditions                                                  ICAO GNSS SARPS.
                 Fault free receiver
                 Remark: The mild ionospheric and troposheric conditions are                   1 A degraded operational conditions (worst       NATS UK



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Paragraph                                        Text                                                            Comment                        Contributor
   No
              defined in the technical models used at system level.                         case) should be considered in order to assess
                                                                                            the performance of Galileo within those
                                                                                            conditions during the certification process,
                                                                                            and
                                                                                            2 Change second - to read, ".....no worse than
                                                                                            those defined in ICAO GNSS SARPS", and
                                                                                            3 Masks shall be defined for each Galileo
                                                                                            signal below which the performance shall be
                                                                                            within specification. However the GPS SPS
                                                                                            mask (which is the only ones current in GNSS
                                                                                            SARPS especially the GNSS-P SARPS as
                                                                                            GNSS-P no longer exists) should not be
                                                                                            assumed for Galileo which could have better
                                                                                            interference performance. It is probable that
                                                                                            by the time ICAO has standardised the
                                                                                            Galileo masks, the system will already have
                                                                                            been built. It is therefore better to define some
                                                                                            mask parameters in this MRD.

                                                                                            Unclear references to interference                  Swiss
                                                                                            environment (currently only defined for L1 in       Federal
                                                                                            the ICAO ANNEX 10 SARPS) and multi-path             Office for
                                                                                            environment. RTCA DO-253 and EUROCAE                Civil Aviation
                                                                                            ED-114 are MOPS relating to GBAS, but
                                                                                            there is no generic MOPS for GNSS.
                                                                                            Better define the references. E.g. ICAO,
                                                                                            Annex 10, Amendment 77, GNSS SARPs
                                                                                            instead of ICAO GNSS-P SARPS. Analogous
                                                                                            with GNSS MOPS. Reference these two
                                                                                            documents in chapter 1.14.

                                                                                            References to existing standards                    STNA


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Paragraph                                           Text                                                            Comment                        Contributor
   No
                                                                                               applicable to GPS L1 only is not
                                                                                               appropriate for Galileo. There will be new
                                                                                               standards produced for Galileo and GPS
                                                                                               L5. Therefore references to ICAO SARP
                                                                                               and receiver MOPS are not pertinent
                                                                                               outside of GPS L1 world. There is a need
                                                                                               to define this environment for the other
                                                                                               Galileo frequencies. Same applies to
                                                                                               multipath.
                                                                                               Fault-free receiver concept does not take
                                                                                               into account for computation time, noise
                                                                                               in the receiver. Here the concept used is a
                                                                                               perfect receiver which is a different
                                                                                               concept.
3.1.4            Service coverage                                                              There is not any mention of altitude; Add           NATS UK
                 The Galileo system shall provide all satellite-only services                  some Maximum altitude depending upon the
                 worldwide ((180° E; 180° W, and 90°S; 90°N).                                  level of services. For aviation I expect that
                                                                                               100,000 ft should be enough for the next 20
                                                                                               years.
3.1.5            Default user Masking Angle                                                    Aviation applications usually uses lower            Swiss
                 Unless specified differently for a particular service, the Galileo            masking angles of 5° with tracking down to 3°       Federal
                 system performance shall apply for all the users having a masking             in order to initialise carrier smoothing filters.   Office for
                 angle no greater than10 degrees.                                                                                                  Civil Aviation
3.1.6            SIS Accuracy Estimation                                                       This should not only take into account clock        NATS UK
                 An estimate of the system inherent pseudo-range error resulting               and ephemeris errors but also other errors
                 from all system errors (e.g. clock and ephemeris errors) for each             affecting satellite depending of failure modes
                 satellite shall be broadcast within the Signals In Space navigation           (for example the so called "evil waveforms")
                 messages in the E5a, E5b and L1 bands..                                       Do not limit this to clock and ephemeris
                                                                                               errors. Galileo integrity must cover all failures
                                                                                               apart from those allocated to the user
                                                                                               receiver.



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Paragraph                                           Text                                                            Comment                        Contributor
   No
                                                                                               SISE should be broadcast on E6.                     STNA
3.2.1            Open Service                                                                  The remark states that the navigation data of       AENA
                 The Galileo Open Service shall be provided free of direct charge.             the Open Service (OS) can be encrypted
                 Remark: The Navigation Data can be encrypted (TBC) in order to                (TBC) in order to ensure a revenue
                 assure a revenue mechanism for the Concessionaire.                            mechanism for the Concessionaire.
                                                                                               In our opinion, this is not a wise decision
                                                                                               since by definition the open service should be
                                                                                               actually open and free to receive!
                                                                                               Furthermore, the Galileo OS should at least
                                                                                               match what GPS already offers on an open
                                                                                               access basis, i.e. the SPS. We believe that
                                                                                               encryption would be counterproductive since
                                                                                               it would endanger the acceptance by the
                                                                                               market.
                                                                                               Moreover, this has a major impact on the
                                                                                               Safety of Life (SoL) service since it is built on
                                                                                               top of the OS by adding integrity. If encryption
                                                                                               were considered, Galileo OS (and SoL) could
                                                                                               have some difficulties for the acceptance in
                                                                                               aviation market.

                                                                                               Encrypting navigation data might serve other        Belgocontrol
                                                                                               purposes than just assuring a revenue
                                                                                               mechanism for the Concessionaire. It is also
                                                                                               a way to protect the system against spoofing.

                                                                                               This is contradictory. If it is provided free of
                                                                                                                                                   NATS UK
                                                                                               direct user charges the signal needs to be an
                                                                                               open signal like GPS and GLONASS. If it is to
                                                                                               be encrypted it would mean the user would
                                                                                               need to pay a direct fee for the de-encryption



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Paragraph                                        Text                                                            Comment                       Contributor
   No
                                                                                            codes. In any case ICAO has rejected on
                                                                                            many occasions the encryption of data only
                                                                                            as it provides no safety benefit while putting a
                                                                                            key management burden on all users. This
                                                                                            requirement is in contradiction with
                                                                                            requirement to be competitive with GPS SPS
                                                                                            and the official implementation of a capability
                                                                                            to code the navigation data would harm ICAO
                                                                                            authorisation to use Galileo. This capability
                                                                                            should not be implemented if civil aviation
                                                                                            users are targeted as potential users by
                                                                                            Galileo. It also is in conflict with EC ICAO
                                                                                            GNSSP Working Paper which stated "It is not
                                                                                            intended that Galileo use encryption on the
                                                                                            SAS for signal denial purposes (commercial
                                                                                            or military)” (Ref: Galileo Signals – Encryption
                                                                                            for Authentication, Presented by the EC
                                                                                            GNSSP Member as WP-72 at the WG-B
                                                                                            meeting of the ICAO GNSS Panel in Seattle,
                                                                                            USA, during the period 29 May-9 June 2000.)

                                                                                            The encryption of the ranging code for             STNA
                                                                                            security reasons has proven to be
                                                                                            useless. The reduction in security level
                                                                                            induced by the user transparent feature
                                                                                            required is such that it is worthless to
                                                                                            implement ranging code encryption for
                                                                                            security reasons.
                                                                                            The encryption of all or part of the
                                                                                            navigation data brings no security
                                                                                            advantage. Encrypting the SIS for
                                                                                            commercial reasons would lead the civil



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Paragraph                                          Text                                                            Comment                        Contributor
   No
                                                                                              aviation community not to use the
                                                                                              encrypted Galileo SISs. It is a major
                                                                                              concern that either OS, SoL or both be
                                                                                              encrypted in part or totally
3.2.1.1.1       Open Service - Positioning and Velocity                                       Even if performance requirements for E5a            AENA
                Mono-Frequency Open Service                                                   and E5b are lower than for L1, they should be
                The Mono-Frequency Open Service shall be provided in either of                included in the document as requirements to
                the three bands L1, E5a, E5b.                                                 be verified.
                Mono-Frequency Open Service                                                   The requirements for availability seem to be
                                                                                              unverifiable.
                The Mono-Frequency Open Service performances are hereafter
                defined when using the Open signals modulated in the L1 band.
                Remark: The Mono-Frequency Open Service performances that                     Despite the statement in 3.2.1.1.1 we now go
                                                                                              on to only define the L1 service with a remark      NATS UK
                can be achieved when using the Open signals modulated in the
                E5a and E5b bands are expected to be slightly lower, due to the               about the other services. I am not sure that
                different ionospheric contribution.(typically: horizontal accuracy            the remark is totally correct as although it
                values of 24 metres and vertical accuracy values of 35 metres)                takes into account the ionospheric
                                                                                              degradation at the lower frequency it does not
                                                                                              detail the improved multi-path performance
                                                                                              obtainable with the higher bandwidths. The
                                                                                              document should therefore consider the use
                                                                                              of E5a & E5b signal in a mono frequency
                                                                                              mode.

                                                                                              OS on E5b is including integrity and high data      STNA
                                                                                              rate which is in contradiction with specification
                                                                                              for mass market applications.
3.2.1.1.1.5     Mono-Frequency Open Service - Availability                                    Global average of availability should be            NATS UK
                The availability of the Mono-Frequency Open Service shall be                  defined. It is not in the definition annex. For
                better than 99.8% (global average) over the nominal operational               example, 99.8% could be 99.9% over 99% of
                lifetime of the system (20 years).                                            the earth and only 89.1% over the remaining
                                                                                              1% which still covers a large part of the
                                                                                              earth's service!!!!!


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Paragraph                                          Text                                                            Comment                     Contributor
   No

                                                                                              There is no requirement concerning               STNA
                                                                                              maximum outage duration. As it is
                                                                                              availability requirements are expressed in
                                                                                              such a way that an outage of 15days
                                                                                              would still be compliant with the MRD,
                                                                                              where as this is obviously not acceptable.
                                                                                              A way to solve this issue would be to have
                                                                                              a maximum outage duration requirement.
                                                                                              In addition the definition of availability
                                                                                              does not explain how mean availability is
                                                                                              computed. It should be specified if it is a
                                                                                              mean value over time, space or both.
3.2.1.1.1.6     Mono-Frequency Open Service - User dynamic                                    The Mono-Frequency Open Service User             EUROCONT
                The Mono-Frequency Open Service shall be provided for a class of              Dynamic is unsuitable for all aviation           ROL
                users and applications characterised by:                                      applications
                Velocity < 500 km/h (138.8 m/s)
                Acceleration < 20 m/s2                                                        What about the interoperability with the         JAA/LBA
                        Jerk < 20 m/s3                                                        current system when using the Open
                                                                                              Service? In the current system the velocity is
                                                                                              up to 800 Knots (1481,6 Km/h).
3.2.1.1.2.1     Dual-Frequency Open Service - Frequencies                                     Or by using the combined E5a and E5b signal      NATS UK
                The Dual-Frequency Open Service performances shall be achieved                to be the E5 and L1 bands. (Based on latest
                by using the Open signals modulated in the E5a and L1-bands, or               Galileo ICD at E5)
                E5b and L1 bands.
                                                                                              The dual frequency open services on L1 and       STNA
                                                                                              E5a or E5b do not have the same
                                                                                              performance due to different data rates on
                                                                                              E5a and E5b. Therefore the first couple of
                                                                                              frequencies should be considered as baseline
                                                                                              for performance assessment. It could also be



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Paragraph                                          Text                                                            Comment                       Contributor
   No
                                                                                              considered that performance should be
                                                                                              verified on both pairs of frequencies (“and”
                                                                                              instead of “or”).
3.2.1.1.2.2     Optimization of navigation codes                                              For aviation we would like the codes               NATS UK
                The navigation codes shall be designed to allow for indoors                   optimised for aviation use. However the
                applications with attenuation dynamics range 30 dB to 35 dB.                  commercial money may be for "in-door" use,
                                                                                              so this should be seen as an off-set against
                                                                                              any proposed aviation costs.
3.2.1.1.2.5     Dual-Frequency Open Service - Velocity Accuracy                               Accuracy in velocity determination needs           NATS UK
                The accuracy in velocity determination available with Dual-                   defining. After iono correction a figure of
                Frequency Open Service (with a 95% confidence level) shall be                 0.1m/s at 1hz might be quite achievable and
                better than (TBD).                                                            highly compatible with the civil aviation
                                                                                              application needs when using velocity
                                                                                              (Navigation does not require Velocity,
                                                                                              Surveillance does and requirement is to
                                                                                              extrapolate position on some short time
                                                                                              period which the suggested specification
                                                                                              should be more than ample in meeting).
3.2.1.1.2.6     Dual-Frequency Open Service - Availability                                    Global average of availability should be           NATS UK
                The availability of the Dual-Frequency Open Service shall be better           defined. It is not in the definition annex. For
                than 99.8% (global average) over the nominal operational lifetime             example, 99.8% could be 99.9% over 99% of
                of the system (20 years).                                                     the earth and only 89.1% over the remaining
                                                                                              1% which still covers a large part of the earths
                                                                                              service!!!!!

                                                                                              a maximum single outage period should be           EUROCONT
                                                                                              defined in addition to the 99.8% global            ROL
                                                                                              average

                                                                                              There is no requirement concerning
                                                                                              maximum outage duration. As it is                  STNA
                                                                                              availability requirements are expressed in


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Paragraph                                          Text                                                            Comment                      Contributor
   No
                                                                                              such a way that an outage of 15days
                                                                                              would still be compliant with the MRD,
                                                                                              where as this is obviously not acceptable.
                                                                                              A way to solve this issue would be to have
                                                                                              a maximum outage duration requirement.
                                                                                              In addition the definition of availability
                                                                                              does not explain how mean availability is
                                                                                              computed. It should be specified if it is a
                                                                                              mean value over time, space or both.
3.2.1.2.1       Timing Open Service - User Environmental Constraints                          Why would the timing open service be              Belgocontrol
                The Timing Open Service level shall be provided for static users,             available only to static users knowing their
                having a Masking Angle no greater than 10 degrees and knowing                 position in the GTRF?
                their position in the Galileo Terrestrial Reference Frame (GTRF).             What about moving users? Doesn’t a static
                                                                                              user need both Galileo signals and Galileo
                                                                                              time to determine his/her position in the
                                                                                              GTRF (Galileo Terrestrial Reference Frame)?
                                                                                              Doesn’t a user need to determine his position
                                                                                              in the GTRF with a minimum accuracy so as
                                                                                              to meet the timing accuracy mentioned in
                                                                                              Section 3.2.1.2.3 (30 nanoseconds)?
3.2.1.2.3       Timing Open Service - Timing Accuracy                                         Previously it had been stated that the            NATS UK
                The timing accuracy of the Timing Open Service shall be less than             specifications are defined using a "fault free"
                30ns (2 σ ) with respect to UTC/TAI over any 24hour period.                   receiver. Now we we have a 2ns receiver
                Comment: This figure includes a 2ns Receiver Error contribution.              error contribution. The document should
                                                                                              attempt to maintain consistency.
3.2.1.2.4       Timing Open Service – Frequency Accuracy                                      Do you mean 3 x 10-13 HZ?                         NATS UK
                The frequency accuracy of the Timing Open Service, expressed as
                a normalised frequency offset relative to UTC, averaged over any
                24 hour period, shall be better than 3 x 10-13 (2 σ ), without any
                other external aids.
3.2.1.2.5       Timing Open Service - Availability                                            Global average of availability should be          NATS UK



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Paragraph                                             Text                                                            Comment                      Contributor
   No
                   The availability of the Timing Open Service shall be better than              defined. It is not in the definition annex. For
                   99.8% (global average) over the nominal operational lifetime of the           example, 99.8% could be 99.9% over 99% of
                   system (20 years)..                                                           the earth and only 89.1% over the remaining
                                                                                                 1% which still covers a large part of the
                                                                                                 earth's service!!!!!
3.2.1.3            Time To Fix                                                                   1 To be acceptable from an aviation receiver      NATS UK
                   TTF Cold Start                                                                point of view, it should be clear that the time
                   The Open Service shall facilitate a Time To Fix performance in cold           to acquire almanac or ephemeris through the
                   start better than 100 seconds.                                                signals as defined in the ICD less an
                                                                                                 acceptable margin for the processing within
                   TTF Warm Start
                                                                                                 the receiver is given. Therefore it is
                   The Open Service shall facilitate a Time To Fix performance in                recommended that the time to acquire
                   warm start better than 30 seconds.                                            Almanac and ephemeris detailed in the ICD
                   TTF in Reacquisition Mode                                                     should be given here, and
                   The Open Service shall facilitate a Time To Fix performance in                2 The Time to fix are defined without specific
                   reacquisition mode better than 1 second.                                      requirement on the frequency to be used. Add
                                                                                                 in the requirement that TTF is defined in
                                                                                                 nominal mode with the two frequencies
                                                                                                 available and no interference environment.

                                                                                                 Is ‘Reacquisition Mode’ a synonym for ‘Hot
                                                                                                 Start’? If yes, use ‘Hot Start’ instead.          Belgocontrol
                                                                                                 Otherwise provide a definition of
                                                                                                 ‘Reacquisition Mode’ in Annex 4.
3.2.2.1.1           SoL - Integrity                                                              It would be more useful if the Galileo system     NATS UK
                   The SoL service shall provide integrity information at global level           was fully certified so that its performance was
                   based upon the monitoring of all the Open Service signals and thus            exactly defined. It may be more cost
                   shall be based upon the navigation performance of the Open                    economic that the system does not provide its
                   Service.                                                                      own integrity and that this is done by
                   Remark: The definitions of integrity and of the associated                    local/regional elements. A cost/benefit
                   parameters are in Annex 4 – Definitions.                                      analysis should be performed. IN ANY CASE
                                                                                                 AVIATION WILL NOT WANT THE COST


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Paragraph                                          Text                                                            Comment                       Contributor
   No
                                                                                              BURDEN OF PROVIDING GALILIEO
                                                                                              INTEGRITY (~€1B capital + €(A lot) revenue)
                                                                                              ON ITS SHOULDERS - there are cheaper
                                                                                              more cost effective ways of providing this
                                                                                              service.
3.2.2.1.2       SoL Integrity Broadcast                                                       The concept of integrity flag has not been         AENA
                The SoL integrity flag data shall be broadcast in the L1 and E5b              previously introduced. Please include it.
                bands.
                                                                                              To maintain interoperability with GPS L5 as        NATS UK
                                                                                              far as possible it would be useful if the
                                                                                              integrity broadcast were transferred to E5a, if
                                                                                              it is to be broadcast at all.
3.2.2.1.3       SoL – Allocation of Integrity Performances                                    Referring to paragraph 3.1.6 it seems that the     NATS UK
                The SoL integrity provision shall be based on the Ground Integrity            Ground Integrity Channel only includes clocks
                Channel concept.                                                              and ephemeris errors, in which case can it
                Remark: The Ground Integrity Channel (GIC), concept is based on               really be considered an integrity channel? It is
                a continuous monitoring of all the Open Service signals by a                  in fact really a Ground Warning (or Notice)
                ground segment, providing so called “integrity” information in near           Channel. In fact other contributions should be
                real-time to the users via the Signal In Space.                               covered by this including SV failures and
                                                                                              others (apart from those allocated to the user
                                                                                              receiver to resolve).
3.2.2.1.4 :     SoL – Protections provided by the system                                      See 3.2.2.1.3 above                                NATS UK
                The Ground Integrity Channel shall protect users against the errors
                due to Signals In Space generation (e.g. clocks and ephemeris)".
                Remark: The errors due to signal propagation or to the receiver
                shall be mitigated at the receiver level by means of additional
                techniques (e.g. Receiver Autonomous Integrity monitoring)

3.2.2.1.5       SoL – Service Guarantee                                                       The Civil Aviation-Airlines, Air Traffic Service   NATS UK
                The Galileo Operating Company shall provide a service guarantee               Providers & Civil Aviation Regulatory
                for the SoL service, as defined in the Legal Annex 1.                         Authorities need to see this Legal Annex as it



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Paragraph                                          Text                                                            Comment                        Contributor
   No
                                                                                              could have severe impact on any one or all.
3.2.2.1.6/7     Authentication (TBC)                                                          Authentication feature could be acceptable          AENA
                The system shall have the capability to authenticate the integrity            from aviation point of view as long as it does
                data broadcast in E5b and L1, by a digital signature, used in the             not imply the encryption of the signals (even
                SoL service to allow the users to verify that the received signal is          partially) and iIt does not imply the increase of
                the actual Galileo signal.                                                    the receiver complexity
                Authentication aspects (TBC)
                The system will have the capability to activate or deactivate the             Quote from the ICAO Working Paper ICAO
                                                                                              NSP WG-1 Flimsy 6C, Nov 2003: If                    DFS
                authentication feature and such capability will be transparent and
                non-discriminatory to users and shall not introduce any degradation           authentication is introduced, then a public key
                in performances.                                                              system that sends the data in the clear should
                                                                                              be used so that authentication is optional for
                                                                                              the user. In other words a failure in the key
                                                                                              management system should be fail passive
                                                                                              and not prevent the user from using the
                                                                                              signals.
                                                                                              Safety and practicability of operations shall
                                                                                              not be compromised

                                                                                              What about adding a digital signature also to       Belgocontrol
                                                                                              the navigation data so as to allow the users to
                                                                                              verify that it is coming from Galileo as well?
                                                                                              An anti-spoofing mechanism could be
                                                                                              implemented that way.

                                                                                              The Authentication feature is highly desired        LFV -
                                                                                              as a low cost means of Anti-spoofing, which         Sweden
                                                                                              only increases the cost of a receiver with a
                                                                                              few Euros.
                                                                                              The handling of crypto keys is simplified to
                                                                                              the degree that the receiver, without any



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Paragraph                                          Text                                                            Comment                      Contributor
   No
                                                                                              manual intervention, changes the keys in co-
                                                                                              ordination with the ground station. The crypto
                                                                                              key can be solved by a hacker but only with a
                                                                                              lengthy method, during which time the crypto
                                                                                              key has been changed.
                                                                                              It is important that the Authentication feature
                                                                                              does not exclude any users from the SoL
                                                                                              service. But for those SoL users with higher
                                                                                              requirements (e.g. for approach and landing)
                                                                                              the availability of Authentication will be of
                                                                                              great value

                                                                                              The civil aviation community considers            STNA
                                                                                              that authentication could be acceptable on
                                                                                              the assumptions that the use of it is
                                                                                              optional and that the data throughput
                                                                                              required for it is acceptably low with
                                                                                              regards to the associated reduction of
                                                                                              robustness to interference.
                                                                                              Authentication bits should not entail a
                                                                                              significant increase of nav data rate.
3.2.2.1.8       Safety of Life Navigation Data Encryption                                     1 The sentence does not seem complete, and        NATS UK
                The system shall have the capability to encrypt the Safety of Life            2 ICAO has rejected on many occasions the
                navigation data (Integrity data) with.                                        encryption of data only as it provides no
                                                                                              safety benefit while putting a key
                Remark: The basic navigation data could also be encrypted (TBC),              management burden on all users. This
                in order to ensure revenue generation for the concessionaire (See             requirement is in contradiction with
                Requirement 0)                                                                requirement to be competitive with GPS SPS
                                                                                              and the official implementation of a capability
                                                                                              to code the navigation data would harm ICAO
                                                                                              authorisation to use Galileo. This capability
                                                                                              should not be implemented if civil aviation


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Paragraph                                        Text                                                            Comment                       Contributor
   No
                                                                                            users are targeted as potential users by
                                                                                            Galileo. It also is in conflict with EC ICAO
                                                                                            GNSSP Working Paper which stated "It is not
                                                                                            intended that Galileo use encryption on the
                                                                                            SAS for signal denial purposes (commercial
                                                                                            or military)” (Ref: Galileo Signals – Encryption
                                                                                            for Authentication, Presented by the EC
                                                                                            GNSSP Member as WP-72 at the WG-B
                                                                                            meeting of the ICAO GNSS Panel in Seattle,
                                                                                            USA, during the period 29 May-9 June 2000.)

                                                                                            Remove the word ‘with’ at the end of the first     Belgocontrol
                                                                                            sentence or complete the sentence.
                                                                                            Encryption not only ensures revenues for the
                                                                                            concessionaire; it also allows the provision of
                                                                                            an anti-spoofing mechanism.

                                                                                            In line with previous argumentation, the           AENA
                                                                                            inclusion of a data encryption facility on SoL
                                                                                            signals has no basis in any of the technical
                                                                                            definition work or user consultation done to
                                                                                            date. It is an unnecessary complication that
                                                                                            will diminish the trust of the SoL user
                                                                                            community, thus creating a barrier to market
                                                                                            penetration. Where has this requirement
                                                                                            come from?
                                                                                            From the aviation point of view, ICAO has
                                                                                            described the encryption of data as not
                                                                                            desirable at many occasions as it provides
                                                                                            no safety benefit while putting a key
                                                                                            management burden on all users. This
                                                                                            capability should be justified if civil aviation



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Paragraph                                          Text                                                            Comment                       Contributor
   No
                                                                                              users are targeted as potential users by
                                                                                              Galileo. We strongly recommend removal of
                                                                                              this requirement.

                                                                                              Encryption and Revenue Generation are both         Swiss
                                                                                              very problematic for an Aviation Safety of Life    Federal
                                                                                              service. Under current charging principles, it     Office for
                                                                                              may be impossible to charge users for this         Civil Aviation
                                                                                              service, leaving service providers in a position
                                                                                              where they are unable to offer services based
                                                                                              on Galileo.

                                                                                              The encryption of integrity data is counter
                                                                                              productive. The encryption of basic                STNA
                                                                                              navigation data is unacceptable.
3.2.2.1.9       Prediction of Availability                                                    For Aviation use, this Prediction should be        LFV -
                Galileo shall inform SoL users about future availability of the               harmonised with the ICAO NOTAM system in           Sweden
                service by the SIS via information provided by the Galileo Ground             order to preclude different sources of
                Segment.                                                                      information when a pilot is planning his flight.
                Remark: Prediction time TBD and False alarm probability TBD.
3.2.2.2.1       SoL Dual Frequency Service                                                    The combined use of E5a+E5b and L1 would           Belgocontrol
                The Dual Frequency SoL Service shall be based on one of the                   indeed provide much more robustness to the
                following combination of frequencies:                                         SoL service users. It would also facilitate the
                E5b and L1.                                                                   implementation of regional and local
                                                                                              mechanisms to protect the service against
                E5a and L1
                                                                                              intentional and/or unintentional interferences.
                Remark: The use of the combination E5a+E5b and L1would offer a
                                                                                              Make sure this ‘option’ is included for civil
                service giving extra robustness to the SoL users as it allows the
                                                                                              aviation purposes in future versions of the
                possibility of using E5a and L1 (when E5bwill not be available) or
                                                                                              MRD.
                E5b and L1 (when E5a will not be available.. This option has not
                been included in this current issue of the MRD but could be
                considered in future versions as a result of the user consultation            1 If user communities (including civil aviation)   NATS UK


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Paragraph                                        Text                                                            Comment                      Contributor
   No
              and mission consolidation processes.                                          have asked for integrity on E5a, why are we
              Remark: The need of having a SoL dual frequency service based                 being ignored. We are told that Galileo is
              E5a + L1 has been requested by the user communities. Although                 being provided to satisfy civil user
              the integrity information will be broadcast in L1 and E5b only as             requirements but for this aspect the civil user
              specified in the requirement 0 (SoL integrity broadcast), the                 community is always ignored - Why? Are you
              integrity information broadcast in L1 shall be the based on the               asking our opinion or telling us what we are
              monitoring of all the Open service signals (including the E5a band)           going to get (if we like it or not!!!!!!), and
              as specified in requirement 0 (SoL – Integrity)                               2 Civil aviation will use (Eurocae WG-62) L1
                                                                                            and E5a and E5b as baseline. Integrity
                                                                                            information generated by monitoring several
                                                                                            signals and transmitted on one may lead to
                                                                                            decrease of availability depending on the
                                                                                            failure modes of the satellites, and
                                                                                            3 First Remark associated to dual frequency
                                                                                            services is confusing. Even without this
                                                                                            remark it is possible to define receivers that
                                                                                            may switch to one service E5x+L1 to the
                                                                                            other in case of interference on one of the
                                                                                            E5x channels. This needs some frequency
                                                                                            separation /protection between E5a and E5b.
                                                                                            If the intent is to promote use of both signals
                                                                                            as coherent sources, it should be stated as
                                                                                            such and interest to be confirmed. Benefit of
                                                                                            such E5A+E5B configuration should be
                                                                                            confirmed before, as well as compatibility with
                                                                                            E5a/E5B separation.

                                                                                            Transmitting integrity information on a SIS       STNA
                                                                                            valid for other SIS has an impact in terms of
                                                                                            data rate and of availability. It therefore may
                                                                                            not be optimal to transmit on L1 an aggregate
                                                                                            integrity for L1, E5a and E5b which would not



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Paragraph                                             Text                                                            Comment                        Contributor
   No
                                                                                                 be able to distinguish independent integrity
                                                                                                 failures.
3.2.2.2.2          SoL Mono Frequency Service                                                    If integrity information is not transmitted on      DFS
                   The Mono Frequency SoL Service shall be based on the use of one               E5a, it is recommended to consider the
                   of the following frequencies:                                                 exclusion from E5a in aviation receivers to
                   E5b or L1                                                                     avoid unnecessary receiver complexity.
                   Remark: A mono frequency SoL service based on E5a has not
                   been considered, as the integrity information will be broadcast in L1         See previous remarks concerning integrity on
                                                                                                                                                     NATS UK
                   and E5b only as specified in the requirement 0 (SoL integrity                 E5b.
                   broadcast),
3.2.2.3            Safety of Life Service Levels for integrity.                                  Since Level A is intended to cover operations       Belgocontrol
                   The Safety of Life service shall allow the operations in different            with ‘very stringent dynamic conditions and
                   transport application domains, (e.g. air, land, maritime, rail), with a       short exposure time’, it seems that Level A
                   wide range of requirements in terms of integrity performances, and            addresses an area usually referred to as
                   generating different constrains at the system level The consultation          Real-Time Kinematics (RTK) applications.
                   of user communities has lead to the identification of the following 3         Right?
                   categories of integrity requirements:
                   Level A shall cover operations, requiring horizontal and/or vertical          In ‘Level C’ please replace ‘costal’ by ‘coastal’   AENA
                   guidance, with short exposure time, and with very stringent
                   dynamic conditions, for example, in the aviation domain approach              Request that the result of the ESTEC-GISS
                   operations with vertical guidance (APV II). It also covers some rail          present work on the consolidation of the            LFV Sweden
                   and road applications.                                                        Integrity Concept is made available for
                   Level B shall cover aviation operations in the range from en-route            comments as soon as the work is finished.
                   to NPA (Non Precision Approach).
                   Level C shall cover maritime operations including ocean navigation,           This should be specified for both mono and          NATS UK
                   costal navigation, port approach, restricted waters and inland                dual frequency service as some safety
                   waterways.                                                                    applications use single frequency GPS
                   Remark: A “user driven” approach has been adopted to identify                 service. It is not clear if this specification
                   these 3 levels to facilitate the mapping between the Galileo mission          applies to single, dual or both single and dual
                   objectives and the applications that Galileo will support in the              frequency service.
                   different applications domains.



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Paragraph                                          Text                                                            Comment                         Contributor
   No
                Nevertheless, from a system implementation perspective, it is                 This MRD version seems not to have been
                necessary to derive the most demanding integrity requirements                 recently updated on a number of points.              STNA
                when preparing the SRD. This exercise is totally dependent on                 There are still references to ongoing work
                some implementation aspects such as the consolidation of the                  between ESTEC and GISS which does not
                integrity concept that is now under analysis by ESTEC and the                 exist for more than one year. This does
                GISS (White paper on integrity) and the definition of a reference             not seem credible. References in this
                receiver.                                                                     document to work going on with GISS
                Depending on the results of the ESTEC-GISS joint effort on the                does not give confidence in the update of
                consolidation of the integrity concept a more generic mission                 this document
                definition regarding integrity will be pursued to facilitate the MRD          The integrity concept not being frozen at
                verification process and the MRD –SRD traceability process.                   phase C0 is concerning.
3.2.2.4.        User Dynamic Conditions                                                       Why specifying a roll and pitch angle here?          Belgocontrol
                User dynamics for the level A.                                                So far, there is no difference between the roll
                The SoL service for the level A is characterised by dynamic                   and pitch angle for Levels A and C?
                environments, up to:                                                          Make sure this is correct. Level A is intended
                         Velocity: 250 knots (463 Km/h, 128.6 m/s)                            for users with short exposure time and very
                         Horizontal acceleration: 2g                                          stringent dynamic conditions.
                         Vertical acceleration: 1.5g
                         Roll and pitch angle = 25 degrees.                                   Similar to 3.2.2.3, this should be specified for
                                                                                                                                                   NATS UK
                                                                                              both mono and dual frequency service as
                         Total jerk: 0.74g/s
                                                                                              some safety applications use single frequency
                User Dynamics for the level B.                                                GPS service. It is not clear if this specification
                The SoL service for the level B is characterised by dynamic                   applies to single, dual or both single and dual
                environments, up to:                                                          frequency service.
                         Velocity: 800 knots (1481,6 Km/h, 411.5 m/s)
                         Horizontal acceleration: 2g                                          According to JAA AMC 25.1329 Section 4.3c            LBA
                         Vertical acceleration: 1.5g                                          (Autopilots) the values for Roll and Pitch are
                         Roll and pitch angle = 25 degrees.                                   as follows: Roll +/- 35 degrees, Pitch +20 to -
                         Total jerk: 0.74g/s                                                  10 degrees, this should be corrected in the
                User Dynamics for the level C.                                                document
                The SoL service for the level C is characterised by dynamic                                                                        EUROCONT


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Paragraph                                             Text                                                            Comment                        Contributor
   No
                   environments, up to:                                                          The User Dynamics for SoL Level A is                ROL
                          Velocity: 250 Knots (463 km/h, 128,6 m/s) (TBC)                        unsuitable for aircraft operations in terminal
                          Horizontal acceleration: 2g (TBC)                                      airspace in anything other than straight-in
                          Roll and pitch angle = 25 degrees (TBC)                                approaches. 25 degrees angle of bank is a
                                                                                                 normal operation - at least 30-35 degrees
                          Total jerk: : 0.74g/s (TBC)
                                                                                                 angle of bank must be accommodated for
                   Remark: Values to be confirmed by the ERMF.                                   abnormal conditions (e.g. high wind) Aircraft
                                                                                                 may fly faster than 250 kts in terminal
                                                                                                 airspace outside final approach and missed
                                                                                                 approach
                                                                                                                                                     Swiss
                                                                                                 Are future supersonic passenger aircraft            Federal
                                                                                                 excluded to use SoL sercives?                       Office for
                                                                                                                                                     Civil Aviation
                                                                                                 Though ships have made significant
                                                                                                 progresses, the maritime user dynamic               STNA
                                                                                                 should be reviewed to come to more realistic
                                                                                                 figures. Is there really a maritime mobile
                                                                                                 having such dynamic capabilities ?
3.2.2.5            Environmental Conditions                                                      1 JTIDS also operates at sea from frigates,         NATS UK
                                                                                                 aircraft carriers, launches, helicopters, fighter
                                                                                                 and command & control aircraft. This means
                                                                                                 that 3.2.2.5.3 should also be applicable to
                                                                                                 levels c for JTIDS (high sea). For inland
                                                                                                 waterways and coastal waters both 3.2.2.5.2
                                                                                                 and 3.2.2.5.3 applies to level C.
                                                                                                 2 Atmospheric conditions such as ionospheric
                                                                                                 and tropospheric conditions need to be
                                                                                                 detailed in this section. There is an additional
                                                                                                 interference requirement for safety of life
                                                                                                 services. This is that no external interference,
                                                                                                 including interference in excess of the


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Paragraph                                          Text                                                            Comment                       Contributor
   No
                                                                                              interference masks, shall cause hazardous or
                                                                                              misleading information.
3.2.2.5.1       Multipath Conditions                                                          Who will define the multipath requirements for     AENA
                Multipath requirements shall be detailed for SoL applications at              each application and when?
                system level to cover both ground and mobile carrier multipath.
                                                                                              What is understood by ‘both ground and             Belgocontrol
                                                                                              mobile carrier multipath’?
                                                                                                                                                 Swiss
                                                                                              Why is the multipath environment restricted to     Federal
                                                                                              carrier multipath? Code multipath is much          Office for
                                                                                              more significant.                                  Civil Aviation
3.2.2.5.2/3     Interferences on the L1 Band                                                  1 ICAO L1 mask is only valid for a BPSK 2          NATS UK
                Galileo Safety-of-Life Service Performances shall be achieved with            signal with received power of –160dBW. It is
                any level of external interference compatible with the ICAO masks             not applicable as is to a BOC(2,2) signal (or
                for interference in the L1 band.                                              even necessarily the know current BOC (1,1)
                Remark: This requirement applies to levels A and B.                           signal).
                Interference - DME                                                            2 The definition of resistance to interference
                                                                                              is different for L1 and E5. This is probably due
                Galileo Aeronautical Safety-of-Life Service Performances shall be
                                                                                              to the fact that the interference mask for L1 is
                achieved with full deployment of the ICAO DME system as well as
                                                                                              already defined for GPS. In principle the
                operations of JTIDs/MIDs , in the “E5a” and “E5b” frequency bands,
                                                                                              requirements are the same except that known
                Remark: This requirement applies to levels A and B.                           sources of pulse interference exist in the E5
                                                                                              band. However there are other potential
                                                                                              sources of interference in the E5 band such
                                                                                              as radar systems operating above 1215 MHz.
                                                                                              There is a need to address this interference in
                                                                                              the E5 band.
                                                                                              3 No GNSS signal can be used in any
                                                                                              possible JTIDS/MIDS configuration. There is
                                                                                              no ICAO deployment scheme for DME.
                                                                                              Therefore, specific masks should be defined



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Paragraph                                          Text                                                            Comment                          Contributor
   No
                                                                                              for these signals : E5a, E5b and alternative
                                                                                              BOC E5a+b, for each channel data / pilot.

                                                                                              JTIDs/MIDs is a US Military system.                   Belgocontrol
                                                                                              Do we have sufficient information on it to
                                                                                              achieve the required Galileo Aeronautical SoL
                                                                                              service performances?
                                                                                              What is understood by the Galileo
                                                                                              ‘Aeronautical’ SoL service? Is this a more
                                                                                              specific version of the Galileo SoL service?

                                                                                              JTIDS/MIDS scenarios for its use have to be
                                                                                              specified to establish RFI budget links.              STNA

                                                                                              Due account needs to be taken of the
                                                                                              potential increase in DME requirements in             IFATCA
                                                                                              ECAC arising from the development of RNAV
                                                                                              operations.
3.2.2.6 to §                                                                                  Specification of the availability of the SoL          AENA
3.2.2.9                                                                                       services is missing (only availability of
                                                                                              accuracy and availability of integrity are
                                                                                              mentioned).
                                                                                              In addition, the requirements specified for
                                                                                              availability of integrity are quite difficult to be
                                                                                              verified.
3.2.2.6.1       SoL- Accuracy and Velocity performances                                       There is no mention of service availability           NATS UK
                                                                                              which is what the user is really looking for.
3.2.2.6.2       SoL -Performance Conditions                                                   It is important that the Integrity signal is          LFV Sweden
                The performances of the SoL service shall be met under the                    broadcast from such a number and spread of
                operational conditions defined in sections 3.2.3.5 environmental              MEO satellites that the signal is able to be
                                                                                              received at all times and at all points globally


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Paragraph                                          Text                                                            Comment                         Contributor
   No
                conditions and 3.2.3.4. User dynamic conditions.                              from at least two MEO satellites in view from
                Remark: No specific requirement on the number of MEO satellites               the receiver.
                broadcasting integrity is included in this MRD. The compliance of
                the continuity risk requirements under the specified operational              Two sv need to be visible at any time for
                conditions will derive the system implementation issues (e.g. the             integrity reason to cover errors in the              NATS UK
                number of MEO satellites broadcasting integrity).                             transmission path. Additionally availability and
                                                                                              continuity performance of integrity needs to
                                                                                              be met.

                                                                                              Make sure the sections that are referred to
                                                                                              here are correctly identified. Their section
                                                                                              numbers and titles do not agree                      Belgocontrol
3.2.2.6.3       Acquisition Requirements.                                                     Acquisition requirements are defined as              NATS UK
                SoL - TTF in Cold Start                                                       associated to standardised interference
                The Time To Fix performance in cold start of the SoL service level            environment and in dynamics conditions while
                shall be better than 100 seconds under the operational conditions             in paragraph 3.1.3 there was no indication of
                defined in sections 3.2.3.4. (environmental conditions) and 3.2.3.3.          an interference environment to be considered
                (user receiver dynamics).                                                     for SOL performances . At the same time it is
                                                                                              still not clear if figures apply to acquisition on
                SoL - TTF in Warm Start
                                                                                              each of the two frequencies or if the easiest
                The Time To Fix performance in warm start of the SoL service level            one for acquisition may be used. There is a
                shall be better than 30 seconds under the operational conditions              need to differentiate between E5 and L1
                defined in sections: 3.2.3.2. (environmental conditions) and 3.2.3.3.         acquisition time. Also it is necessary to take
                (user receiver).                                                              into account interference impact on TTF if
                SoL - TTF in Reacquisition Mode                                               interference environment is included.
                The Time To Fix performance in reacquisition mode of the SoL                  The final paragraph seems out of place. It is
                service level shall be better than 1 seconds when no integrity alarm          difficult to understand the link between TTF
                has been raised by the system in the last 30 seconds SoL –                    and integrity. This must be an editorial error.
                Allocation of Integrity Performances.                                         Perhaps it belongs to the next section
                The apportionment of integrity performances (Integrity Risk),                 3.2.2.7?
                between the Signals In Space and the receiver shall be compliant
                with relevant standards in force (e.g. EUROCAE).


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Paragraph                                          Text                                                            Comment                      Contributor
   No
                                                                                              Is ‘Reacquisition Mode’ a synonym for ‘Hot        Belgocontrol
                                                                                              Start’? If yes, use ‘Hot Start’ instead.
                                                                                              Otherwise provide a definition of
                                                                                              ‘Reacquisition Mode’ in Annex 4. What are
                                                                                              the expected TTF performances in
                                                                                              reacquisition mode if an integrity alarm has
                                                                                              been issued within the last 30 seconds?
                                                                                              Provide a new requirement entitled ‘Allocation
                                                                                              of Integrity Performances’

                                                                                              Which EUROCAE "standards in force" is             Swiss
                                                                                              being referred to?                                Federal
                                                                                                                                                Office for
                                                                                                                                                Civil Aviation
3.2.2.7.1       Definition of integrity requirements for the service level A.                 The Time To Alarm for the service level A         NATS UK
                Integrity Risk                                                                shall be 6s." This needs its own heading.
                The Integrity Risk for service level A shall be ≤ 2.10-7 per period of
                150s.                                                                         A TTA of 6 seconds seems too long a delay         Belgocontrol
                Remark: This figure does not include the receiver and data base               for users with short exposure time and very
                contribution TTA                                                              stringent dynamic conditions. Was Level A
                The Time To Alarm for the service level A shall be 6s.                        oversold?

                                                                                                                                                Swiss
                                                                                              Use 2*10-7 instead of 2.10-7. The latter can be
                                                                                                                                                Federal
                                                                                              misunderstood as '2 comma 1'. This is valid
                                                                                                                                                Office for
                                                                                              for a lot of risk values within this document.
                                                                                                                                                Civil Aviation

                                                                                              An allocation to the receiver shall be
                                                                                                                                                STNA
                                                                                              included in the TTA computation.
3.2.2.7.2 &     Horizontal Alarm Limit                                                        One does not provide an alarm limit, but one      NATS UK
3.2.2.7.3       The Horizontal Alarm Limit for the service level A is 40 m.                   uses an alarm limit to compare with computed
                Vertical Alarm Limit                                                          protection levels. The SoL multi-frequency


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Paragraph                                             Text                                                            Comment                        Contributor
   No
                   The Vertical Alarm Limit for the service level A is 20 m.                     service in the critical level should be provided
                                                                                                 with the specified performance when using a
                                                                                                 horizontal/vertical alarm limit up to (or of ) xx
                                                                                                 m.
3.2.2.7.5 &        Availability of Integrity                                                     What does availability of integrity mean. If        NATS UK
3.2.2.8.5          The availability of integrity for the service level A shall be at least       integrity is only available 99.5% then the total
                   99.5 % (global average) over the nominal operational lifetime of the          integrity(for this section-similar calculations
                   system (20 years).                                                            for other sections) is 1-(1-2e-7)*(1-.995)=5e-
                                                                                                 3!!!!
                   Availability of Integrity                                                                                                         Swiss
                   The availability of integrity for the service level B shall be at least       This is on the lower end of the range specified
                                                                                                                                                     Federal
                   99.5 % (global average) over the nominal operational lifetime of the          in Annex 10.
                                                                                                                                                     Office for
                   system (20 years).                                                                                                                Civil Aviation

                                                                                                 There is no requirement concerning                  STNA
                                                                                                 maximum outage duration. As is
                                                                                                 availability requirements are expressed in
                                                                                                 such a way that an outage of 15 days
                                                                                                 would still be compliant with the MRD,
                                                                                                 where as this is obviously not acceptable.
                                                                                                 A way to solve this issue would be to have
                                                                                                 a maximum outage duration requirement.
                                                                                                 In addition the definition of availability
                                                                                                 does not explain how mean availability is
                                                                                                 computed. It should be specified if it is a
                                                                                                 mean value over time, space or both.
3.2.2.8            Definition of integrity requirements for the service level B                  Level B is clearly a mono frequency based           NATS UK
                                                                                                 performance level. When two frequency
                                                                                                 signals are available, the performance level
                                                                                                 will be A, so what is the purpose of defining
                                                                                                 Level B with two frequencies available?



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Paragraph                                             Text                                                            Comment                  Contributor
   No
                                                                                                 Suggest that a specification for Level B
                                                                                                 achievable with a single frequency is also
                                                                                                 provided.
3.2.2.8.3          Horizontal Alarm Limit                                                        See note for 3.2.2.7.2.                       NATS UK
                   The Horizontal Alarm Limit for the service level B shall be 556 m.
3.2.2.8.4          Continuity Risk                                                    Continuity of risk in ICAO is dependant on               NATS UK
                   The Continuity Risk for the service level B shall be less than [10-4 –
                                                                                      airspace complexity. I would suggest that as
                   10-8] (TBD) per hour.                                              Europe has the most complex airspace in the
                   Remark: Receiver contribution not included.                        world that we should be asking for the 10e-
                                                                                      8/hour requirement.
3.2.2.9            Definition of integrity requirements for the service level C.      Coherently with integrity requirements for               AENA
                                                                                      service level A and B, integrity risk figure for
                                                                                      service level B should not include database
                                                                                      and receiver
3.2.3.1.5          SAR Return Link Messages                                           What is the impact in terms of TTFF or nav               NATS UK
                   The Search and Rescue service shall transmit SAR Return Link data rate of the addition of the SAR
                   Messages via the Galileo open Navigation signals, broadcast in the acknowledge and long acknowledge ? This is
                   L1 band                                                            in contradiction with the requirement for a
                   Remark: The Return Link message will be supported by the open robust Galileo signal.
                   signal in L1, for compatibility purposes
3.2.3.1.6          SAR Constraints                                                    If the navigation data is to be encrypted, how           NATS UK
                   The Search and Rescue (SAR) service shall be supported as an will the positioning data on SAR be sent - or
                   open service, free of direct charge and non-encrypted.             will the SAR transmitter just re-broadcast
                                                                                      encrypted received signals which will be
                                                                                      calculated at the SAR base. This however
                                                                                      puts additional overhead on the satellite data
                                                                                      handling capacity and could impact on the
                                                                                      robustness of providing a navigation service.
                                                                                      The principle of this needs explaining.
3.2.3.1.8          Safety of Life Navigation Data Encryption                          Encryption offers no benefits to the aviation            EUROCONT
                   The system shall have the capability to encrypt the Safety of Life community - it increases the likelihood of               ROL



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Paragraph                                          Text                                                            Comment                        Contributor
   No
                navigation data (Integrity data) with.                                        system failure and hence decreases the              IATA
                Remark: The basic navigation data could also be encrypted (TBC),              expected availability. Aviation requires a          ERA
                in order to ensure revenue generation for the concessionaire                  system that is NOT encrypted.                       AEA
3.2.3.4.1       User Dynamic Conditions                                                       See comments on 3.2.2.4
                User dynamics for the level A.
3.2.3.4.2       User Dynamics for the level B.                                                See comments on 3.2.2.4
3.2.3.5         Performances                                                                  It should be stated that a minimum of two           STNA
                Detection Probability                                                         satellites transmitting integrity are required as
                Distress signals in the 406 MHz frequency band shall be detected              a consequence of requirement 4.5.6
                with a probability of better than 99%, and shall be transmitted to the
                SAR operational ground station in less than 5 minutes.
                Remark: The detection probability is the most significant parameter
                to qualify this mission. The International Maritime Organisation has
                supported the value of 99.8 %. However, a value of 99 % is
                consistent with both the current SAR operations and with what can
                be realistically achieved at the system level.
3.2.3.5.10      SAR Capacity                                                                  A maximum of 150 active beacons per MEO             Belgocontrol
                The SAR service shall support the processing of a maximum                     satellite with 30 such satellites means a
                number of 150 Cospas-Sarsat simultaneous active beacons per                   maximum of 4500 simultaneous calls for the
                MEO satellite coverage.                                                       whole earth. Depending on the average time
                                                                                              needed to solve such calls, this might not be
                                                                                              enough.
3.2.3.10.1      SoL dual frequency for level A                                                An HAL of 556m could only be expected to            EUROCONT
                See table below                                                               support RNP 0.3 operations in the cheaper           ROL
                                                                                              navigation systems. Within the next 20 years
                                                                                              it is very likely that RNP values <0.3 will be
                                                                                              required to support applications that are not
                                                                                              on a straight-in final approach. It is not clear
                                                                                              how this will be achieved with the current
                                                                                              Galileo criteria.
                                                                                              An integrity risk of 2x10-7 /150 sec is


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Paragraph                                        Text                                                                  Comment                       Contributor
   No
                                                                                                 insufficient for APV II applications. - should be
                                                                                                 at least 1x10-.7.
                                                                     Table 2 - Comments by Paragraph

                              Level A (Aviation APV II         Level B (Aviation          Level C (Maritime
                              road and train                   En-route to NPA)           applications)
                              applications)
     Dual frequency           HAL=40 m                         HAL=556m                   HAL=25m
     E5a+ L1                  VAL= 20m                         TTA=10 sec.                TTA=10 seconds
     or                       TTA=6 seconds                    Int.. Risk=10-             Int. Risk=10-5/3 hours
     E5b+L1                   Integrity Risk=2.10-7/150 s      7
                                                                /hour
                              Continuity risk: 8.10-6 in                                  Continuity risk:
                              any 15 s period.                 Continuity risk:           3.10-4 / 3 h
                                                               [10-4 – 10-8] TBD
                                                               per hour
     Mono frequency            Not achievable.                 HAL=556m                   Not achievable.
     L1                                                        TTA=10 sec.
      or                                                       Int. Risk=10-7/hour
     E5b
                              Coverage:Global                  Coverage: Global           Coverage: Global

 Paragraph No                                        Text                                                           Comment                          Contributor
3.3                Galileo-satellite only and EGNOS combined services                             Galileo may not of itself be sufficient to allow   EUROCONT
                   Remark:                                                                        GNSS to become robust enough for sole              ROL
                   Through this EGNOS upgrade, GALILEO becomes a necessary                        service provision for civil aviation in Europe.
                   condition to allow GNSS to become robust-enough for sole-
                   service provision for civil aviation in Europe, and then, in turn, to          This statement using the future tense,             UK CAA
                   further accelerate the decommissioning process of navigation                   implies that there is no doubt whatsoever          SRG
                   ground aids.                                                                   that Galileo (with EGNOS) can become the
                                                                                                  only navigation aid for civil aviation, and that
                                                                                                  (eventually) all ground based aviation
                                                                                                  navigation aids can thus be
                                                                                                  decommissioned, i.e. no conditions have


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                                                                                                been placed on this particular move. It has
                                                                                                not yet been proven that any augmented
                                                                                                GNSS will be robust enough to be a sole-
                                                                                                service (or sole-means) system for aviation,
                                                                                                nor that it follows that ground based aids
                                                                                                can thus be decommissioned more rapidly.

                                                                                                Suggest:

                                                                                                 Through this EGNOS upgrade, GALILEO
                                                                                                may become a GNSS that will be robust
                                                                                                enough for it to be considered as a sole-
                                                                                                service provision for civil aviation in Europe.
                                                                                                However, this will need to be proven and as
                                                                                                with any sole-service provision will require
                                                                                                adequate safety cases. Provided this
                                                                                                occurs, it may then be possible to consider
                                                                                                an acceleration in the decommissioning
                                                                                                process of navigation ground aids .

                                                                                                Any augmented service resulting from a            Belgocontrol
                                                                                                combination of Galileo and EGNOS would
                                                                                                only be available above Europe, not a
                                                                                                particularly attractive business from the civil
                                                                                                aviation viewpoint. Since EGNOS, WAAS,
                                                                                                and MSAS are compatible systems, a real
                                                                                                opportunity exists to design augmented
                                                                                                services that would be available also with
                                                                                                WAAS and MSAS. Are there plans to do
                                                                                                so?
3.3.1                 Galileo SoL and EGNOS service level.                                      Do we really have confidence that it will be      Belgocontrol
                      Level D covers aviation CAT I operations that requires more               possible to perform CAT I operations thanks
                      demanding vertical guidance than level A.                                 to a combination of Galileo and EGNOS
                                                                                                signals without the help of any ground
                                                                                                station whatever the level of interference



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                                                                                               (both intentional and unintentional)? And
                                                                                               once you know that such a service would
                                                                                               not be available world-wide, polar regions
                                                                                               included, would you still embark such a
                                                                                               system on board an aircraft? Will CAT I
                                                                                               operations have to be conducted with a
                                                                                               GBAS in the USA (the LAAS) but with a
                                                                                               SBAS in Europe? Will such a situation
                                                                                               facilitate the standardisation of aircraft
                                                                                               equipment
3.3.1.1.1            Accuracy.                                                                 The MRD requirements should be verifiable.       NATS UK
                     The accuracy for service level D (with a 95% confidence level)            A single performance value should then be
                     shall be better than 16 m (horizontal) and 4-6 m (vertical).              given and not a range of values. Set a single
                                                                                               value for compliance (and hence
                                                                                               certification) assessment.
3.3.1.1.2            Integrity Risk                                                            This integrity value is not as good as Level A   EUROCONT
                     The Integrity Risk for service level D is ≤ 3.5.10-7 per period of                                                         ROL
                     150s.                                                                     Coherently with integrity requirements for
                     Remark: This figure includes the receiver and database                    service level A and B, integrity risk figure     AENA
                     contributions assumed as 1.5 10-7 per period of 150s                      should not include database and receiver. It
                                                                                               should be 2 * 10–7 / h for the SIS.

                                                                                               Same remark as for service level A ,             NATS UK
                                                                                               Integrity risk figure should not include data
                                                                                               base and receiver. It should be 2 10-7/h for
                                                                                               the SIS . Remove receiver part from this
                                                                                               integrity requirements.

                                                                                               The integrity risk for service Level D is less   Belgocontrol
                                                                                               stringent than the one requested for service
                                                                                               Level A? Make sure this is correct
3.3.1.1.4 &          Horizontal Alarm Limit                                                    One does not provide an alarm limit, but one     NATS UK
3.3.1.1.5            The Horizontal Alarm Limit for the service level D is 40 m.               uses an alarm limit to compare with
                     Vertical Alarm Limit                                                      computed protection levels. The SoL multi-
                     The Vertical Alarm Limit for the service level D is 12 m.                 frequency service in the critical level should


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                                                                                                  be provided with the specified performance
                                                                                                  when using a horizontal/vertical alarm limit
                                                                                                  up to (or of ) xx m.

                                                                                                  12 m VAL for Cat I has not been adopted by       NATS UK
                                                                                                  ICAO yet and may need further validation.
                                                                                                  Add a note to this effect.

                                                                                                  12 m VAL for Cat I has not been adopted by       AENA
                                                                                                  ICAO yet and may need further validation.
                                                                                                  Please, add TBC.

                                                                                                  Annex 10 specifies a range from 10 to 15m.       Swiss
                                                                                                  What is the rationale in defining 12m within     Federal
                                                                                                  the MRD?                                         Office for
                                                                                                                                                   Civil Aviation
3.3.1.1.7               Availability                                                              Why is the text different than in other          LBA
                        The availability for the service level D is at least 99.5 %. (TBC)        paragraphs? The following text should be
                                                                                                  added for consistency: …(global average)
                                                                                                  over the nominal operational lifetime of the
                                                                                                  system (20 years).

                                                                                                  This is on the lower end of the range            Swiss
                                                                                                  specified in Annex 10.                           Federal
                                                                                                                                                   Office for
                                                                                                                                                   Civil Aviation
3.3.1.2                 Requirements for Galileo SoL and EGNOS.                                   It is not clear if the level of performance to   NATS UK
                        It is expected that the Galileo SoL Dual Frequency service, as            be provided by the combination of EGNOS
                        defined in section .., when combined with the EGNOS service,              and Galileo is a requirement. This section
                        as defined in the EGNOS MRD (RD 5), will meet the                         uses the wording “it is expected that …”.
                        requirements of level D, as defined in section .., in the EGNOS           How will this “requirement” be reflected in
                        service area as defined in the EGNOS MRD.                                 the Galileo SRD? It needs to be clarified if
                                                                                                  this is a requirement or not. As currently
                                                                                                  worded it should be a remark.




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                                                                                                  This is not a requirement. It should be           STNA
                                                                                                  written as a remark.
3.4                     LOCALLY ENHANCED SERVICES                                                 Furthermore, the various levels of                NATS UK
                                                                                                  performance enhancement offered and the
                                                                                                  different combinations of service make it
                                                                                                  impossible to comprehensively define all
                                                                                                  such Locally Enhanced Services."
                                                                                                  Frequencies for Galileo Local components
                                                                                                  are not specified. Availability of ARNS
                                                                                                  frequency bands for such services should be
                                                                                                  investigated and requested for allocation.
3.4.1.4                 Local Service Interference                                                This is a very good requirement which we          Swiss
                        Any Galileo local service shall not degrade in any way the                strongly support. In particular, we fear that a   Federal
                        performance of the Galileo Satellite only services, or other              proliferation of commercial local services        Office for
                        Galileo Local Services.                                                   may have negative impacts on SoL /                Civil Aviation
                                                                                                  Aviation Local Services. This issue will have
                                                                                                  to be addressed very carefully, and brings
                                                                                                  up the issue of control over local element
                                                                                                  provision. The MRD levies requirements on
                                                                                                  Galileo itself, but not on local service
                                                                                                  providers. What regulatory mechanism is
                                                                                                  foreseen to make sure that local element
                                                                                                  providers comply with this requirement?
3.4.2                   Reference Application Service Levels                                      The deployment of an Advanced Surface             Belgocontrol
                                                                                                  Movement Guidance and Control System is
                                                                                                  another application that would greatly
                                                                                                  benefit from a local component.
3.4.2.1                 Aviation Precision Approach                                               Requirements included for local component         AENA
                        Remark: The level of requirements quoted below are indicative             for aviation are not in line with the
                        of those currently being elaborated for Category III precision            requirements under development in
                        approaches, and are based upon equivalent ILS and MLS                     RTCA/Eurocae for GBAS CAT II/III.
                        requirements. This application has been chosen as a reflection            If the aim of the Local component for
                        of the typical usage of Differential Code as a means to meet the          aviation is support of CAT II/III operations,
                        positioning requirements. As a basis it is likely to use the Galileo      the requirements should be in line with those
                        SOL dual-frequency service.                                               requirements that ICAO will publish for this


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                                                                                        precision approach. The ICAO GNSSP,
                                                                                        EUROCAE WG28 and RTCA SC-159 are
                                                                                        currently developing the high-level
                                                                                        performance requirements for GNSS-based
                                                                                        Category II/III operations. However, at this
                                                                                        moment not final result has been achieved.
                                                                                        In order to not penalise the development of
                                                                                        the Galileo Local component with very
                                                                                        stringent requirements, it would be
                                                                                        necessary too co-ordinate this requirement
                                                                                        with those accepted by the aviation
                                                                                        community.

                                                                                        Stating that differential code tracking          Belgocontrol
                                                                                        (DGPS) is the right technology to be used to
                                                                                        meet the requirements of CAT II/III
                                                                                        operations might be venturing too far (even
                                                                                        in a dual-frequency environment). To the
                                                                                        best of our knowledge, the only civil GBAS
                                                                                        currently under development (the LAAS) is
                                                                                        still not operational and its entry into
                                                                                        operation has been further postponed
                                                                                        (2006). Still, this mono-frequency DGPS
                                                                                        approach only addresses CAT I operations.
                                                                                        Not to speak of the costs of the final product
                                                                                        which surely have grown with the delays.
                                                                                        Instead, carrier-phase tracking might be an
                                                                                        option here especially in a multi-frequency
                                                                                        environment because such an environment
                                                                                        facilitates the resolution of integer
                                                                                        ambiguities. That the technology works for
                                                                                        CAT III operations has been proven in April
                                                                                        2001 by the US Navy’s Joint Precision
                                                                                        Approach and Landing System (JPALS)
                                                                                        when a Super Hornet fighter performed



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                                                                                               several landings on board an aircraft-carrier
                                                                                               thanks to this system.

                                                                                               The performance requirements for aviation       NATS UK
                                                                                               precision approach are known for Category I
                                                                                               operations but are still being determined for
                                                                                               Category II/III operations. All values quoted
                                                                                               here could change. The horizontal accuracy
                                                                                               and alert limit given are unlikely to be
                                                                                               adequate for Category III precision
                                                                                               approach. The vertical alert limit may be
                                                                                               over stringent but this still has to be
                                                                                               determined. There is a need to insert [TBC]
                                                                                               after all requirements stated for aviation
                                                                                               precision approach.

                                                                                               Vertical Requirements seem excessively          Swiss
                                                                                               stringent. Most requirements are copied         Federal
                                                                                               from current GBAS standards, which              Office for
                                                                                               appears sufficient other than that the MRD      Civil Aviation
                                                                                               does not provide sufficient definitions of
                                                                                               these requirements to stand alone.
3.4.2.1.8            Availability                                                              MRD requirement should be verifiable. A         NATS UK
                     The Local Service should provide an availability of between 99 –          single performance value should then be
                     99.999 %.                                                                 given and not a range of values. Set a single
                                                                                               value to assess compliance/certification
                                                                                               requirements. The figure should meet
                                                                                               European major international airport
                                                                                               requirements until the year 2030.

                                                                                               The availability range is given such that the   Swiss
                                                                                               local service provider can choose an            Federal
                                                                                               availability level that is appropriate to the   Office for
                                                                                               application, assuming a baseline                Civil Aviation
                                                                                               constellation performance. The requirement



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                                                                                                  should refer to this baseline, and clarify that
                                                                                                  this range does not apply to Galileo itself.
4.1.1.3                 Compliance with ITU regulations                                           Replace ‘should’ by ‘shall’.                      Belgocontrol
                        The Galileo ground stations operating L or C band should
                        comply with REC ITU-R M1584 and REC ITU-R M1582
                        concerning the separations with radar and MLS stations.
4.1.1.6                 Space and Ground Segment Autonomy                                         Make sure the 2.5 hours maximal delay             Belgocontrol
                        The space and ground segment shall be designed such that the              mentioned here is compatible with TTA
                        operations personnel are made aware of any autonomous                     requirements specified in other parts of the
                        reaction on board of a satellite to an anomaly or external event          document.
                        on ground within 2.5 hours.
4.1.2.2                 Galileo Local Element Standards                                           Are ICAO GBAS SARPS available already?            Belgocontrol
                        Galileo Local Elements shall, where necessary, adhere to all
                        appropriate existing standards (e.g. RTCM signal formats, ICAO            To comply with ICAO GBAS standards,               NATS UK
                        GBAS SARPS etc).                                                          Galileo local elements should specify the
                                                                                                  data link frequency and modulation scheme
                                                                                                  that is intended for use. Additionally GBAS
                                                                                                  is standardised as a GPS based mono-
                                                                                                  frequency system. A new standard will have
                                                                                                  to be generated

                                                                                                  Use proper reference (ICAO Annex 10               Swiss
                                                                                                  SARPS, Section 3.7.3.5). Add RTCA too.            Federal
                                                                                                                                                    Office for
                                                                                                                                                    Civil Aviation

                                                                                                  There are no GBAS requirements for a              STNA
                                                                                                  SIS different from GPS SPS !
4.1.2.4                 Definition of Interfaces Between the Galileo Global and Galileo           It is not clear why it needs be the Galileo       Swiss
                        Local Component                                                           Global Component Designers that are solely        Federal
                        In order to maximise the ease of implementation and use of                responsible for defining a local element ICD.     Office for
                        Galileo Local Elements, ICD’s shall be defined by the system              Given that the global ICD is clear, this          Civil Aviation
                        designers of the Galileo Global Component, between the Galileo            should not be necessary. A certain level of
                        Global Component and external systems that can be used as                 cooperation and mutual information should
                        part of the Galileo Local Component.                                      be implemented, however. Suggest to re-


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                                                                                               phrase this requirement.
4.1.2.5 -            Use of Galileo Local Elements for Interference Detection                  These are all requirements levied on an         Swiss
4.1.2.11             It should be possible for Galileo Local Elements to aid in the            entity external to Galileo, which is not        Federal
                     process of detection and isolation of sources of interference to          possible in a Galileo specification. In         Office for
                     the Galileo SIS, using as a basis interference levels detected by         particular, it may be more efficient to         Civil Aviation
                     them and/or their associated users.                                       perform Interference Detection and
                     Galileo Local Element Recording Functionality                             Performance Recording in a different facility
                     Galileo Local Elements delivering any guaranteed or Local                 than one providing an actual service. Such
                     Safety Of Life service shall implement a data recording function,         statements can at most be
                     in accordance with appropriate modal requirements.                        recommendations, and not requirements.
                     Galileo SOL Local Element Resistance to Interference                      Also, these requirements apply primarily to
                     Galileo Local Elements delivering any Local Safety Of Life                aviation, where these factors are already
                     service shall implement techniques that improve their resistance          established practice. Non-aviation local
                     to interference of the SIS, in accordance with appropriate modal          element requirements are missing.
                     requirements.
                     Galileo Local Element Resistance to Spoofing                              The use of Galileo Local element as an          STNA
                     Galileo Local Element delivering any Local Safety Of Life service         interference detection tool is considered
                     shall implement techniques that guard against the ability for their       as an interesting feature. It is
                     transmissions to be spoofed, in accordance with appropriate               recommended to continue the
                     modal requirements.                                                       investigations in this direction.
                     Local Service Coverage
                     The Local Service broadcast message shall, where necessary,
                     define the local service coverage area for which the nominal
                     level of performance is valid, in accordance with appropriate
                     modal requirements.
                     Network Coverage
                     If necessary, it should be possible to network several individual
                     local elements together to further enhance range and/or
                     accuracy of the local services.
                     Standardisation of the Local Service Air Interface
                     Standardisation activities with respect to Local Services should
                     aim to facilitate the implementation of standard Air Interfaces.
4.1.2.11             Standardisation of the Local Service Air Interface                        What is understood by an ‘Air Interface’?       Belgocontrol
                     Standardisation activities with respect to Local Services should
                     aim to facilitate the implementation of standard Air Interfaces.          There are no frequencies allocated for the      STNA


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                                                                                                  transmission of Galileo differential
                                                                                                  corrections by the local elements. It should
                                                                                                  be requested that filings are placed in this
                                                                                                  perspective by the GJU or the
                                                                                                  concessionaire.
4.1.3.1                 Degree of independence between EGNOS and Galileo                          This requirement is not understood. It should STNA
                        The degree of independence between the EGNOS system and                   be clarified.
                        the Galileo global component shall be driven by the expected
                        performances of the EGNOS and Galileo combined service
                        (defined in section 0.) and based on a failure mode and
                        robustness analysis.
4.1.4                   User Terminal Requirements                                      Requirements on receivers ( as in this                 NATS UK
                                                                                        section ) are out of scope of the MRD. Any
                                                                                        receiver manufacturer for competitiveness
                                                                                        will tune its product to the market without a
                                                                                        need to be made aware of the
                                                                                        recommendation on size and power .
                                                                                        Suggest remove receiver requirements on
                                                                                        size and power consumption.
4.1.4.1.5               Receiver Galileo/GPS Position Computation                       The requirement for OS is to track signals             AENA
                        The OS Galileo receiver shall be able to compute its position   from at least four satellites (GPS + Galileo).
                        (with degraded performances) with n Galileo satellite and m GPS However, integrity through RAIM requires
                        satellite in view (n+m=4).                                      more satellites. This should be mentioned in
                                                                                        any requirement.
4.1.4.2                 SoL Receiver                                                    1 Future EUROCAE MOPS should be                        NATS UK
                        The SoL Galileo receiver shall follow a design to ease the      referred to, and 2 SOL receiver /
                        certification processes.                                        requirement for certification. This is
                                                                                        mandatory for civil aviation and the
                                                                                        requirement “for ease of certification” is not
                                                                                        rigorous enough. SOL receiver should be
                                                                                        designed in accordance with certification
                                                                                        constraints when required in order to meet
                                                                                        the targeted applications.
4.2.1                   Regional Integrity Components                                   The external integrity regions is another              STNA
                                                                                        concern.


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                                                                                                  The need for external integrity regions is
                                                                                                  questioned. This is not a civil aviation
                                                                                                  community requirement. This feature
                                                                                                  leads to increase the data rate required
                                                                                                  to transmit integrity information thus
                                                                                                  reduces robustness and increases TTF in
                                                                                                  reacquisition mode which is increasing
                                                                                                  the impact of the interference threat.
                                                                                                  Another issue is the transmission of the
                                                                                                  applicability area through SIS. This
                                                                                                  supposes that all modes of transport will
                                                                                                  rely on the same geographical repartition
                                                                                                  which may not be the case. In addition
                                                                                                  the transmission of this information
                                                                                                  increases also the navigation data rate.
4.2.1.1                 Broadcast Capability for External Integrity Data                          Five regions will probably not be enough for    NATS UK
                        The Galileo system shall have the capability of broadcasting              civil aviation as each State has its own
                        integrity data computed by up to five regions simultaneously              responsibility. Even dividing the world up
                        using the Galileo satellites.                                             into ICAO regions means a requirement for
                                                                                                  more than five. In addition the aviation
                                                                                                  regions are liable to be different to the
                                                                                                  marine/road regions.
4.2.1.3                 Direct Uplink                                                             There is a potential safety and security        STNA
                        The Galileo system shall allow the Regional Components to                 issue related to this requirement which
                        directly up-link to the MEO satellites the integrity data computed        has not been addressed in the MRD.
                        regionally.
4.2.1.4                 Seamless Navigation                                                       The sentence is not clear.                      Belgocontrol
                        The Galileo signals shall provide the user with information on
                        which the integrity information block is applicable to a given            The geographical applicability may              STNA
                        geographic area.                                                          depend on the transport mode. This has
                                                                                                  an impact on the nav data rate.
4.3.1                   Lifetime                                                                  Life time seems short. Aviation would prefer    Swiss
                        The Galileo services shall be provided for a minimum of 20                indefinite with a minimum notification period   Federal
                        years.                                                                    upon planned termination.                       Office for
                                                                                                                                                  Civil Aviation


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4.5.3.1                 Experiences from EGNOS                                                    The requirement included within this             AENA
                        The relevant experiences from the EGNOS programme shall be                subsection is too generic. Please add some
                        taken into account.                                                       details.
4.5.4.1                 Single Internal Failure Consequences                                      Is the overall system addressed like in          LBA
4.5.4.2                 Redundant Architecture shall be implemented, such that no                 4.5.4.1 or the individual element like a
                        single internal failure has an effect on continuity of the relevant       satellite as in 4.5.4.2? As this is not quite
                        Galileo function.                                                         clear from the current wording, the two
                        Redundant Systems Separation                                              paragraphs are slightly in contradiction to
                        Redundant elements shall be physically and functionally                   each other.
                        separated so as to avoid the propagation of failures.
4.5.6                   Single Misleading Conditions                                              It should be stated that a minimum of two        STNA
                        No single failure, error, external event shall lead to a loss of          satellites transmitting integrity are required
                        integrity.                                                                as a consequence of this requirement.
5.7.2                   Local Element Demonstrator Functionality                                  Demonstrating four functional aspects will       Swiss
                        As a minimum four functional aspects (Differential Code,                  not permit the verification of benefits. The     Federal
                        Differential Carrier, Assisted Galileo and Augmented Galileo)             verification of benefits requires the            Office for
                        shall be addressed in order to verify the various benefits that           development of operational concepts and          Civil Aviation
                        Galileo Local Services will deliver.                                      implementation scenarios.
5.7.2.1                 Galileo Local Element Precision Navigation Functionality                  Refer to the comments made above for             Belgocontrol
5.7.2.2                 A Galileo Local Element shall be developed to verify the                  Section 3.4.2.1.
                        provision of differential code phase corrections to improve
                        accuracy and deliver associated enhanced Local Integrity
                        information, using as a basis the pertinent requirements detailed
                        in Section 3.4.2.1 of the MRD.
                        Galileo Local Element High Precision Navigation Functionality
                        A Galileo Local Element shall be developed to verify the
                        provision of differential carrier phase corrections to improve
                        accuracy, using as a basis the pertinent requirements detailed in
                        Section 3.4.2.2 of the MRD.
                        Remark: Particular emphasis will be placed on TCAR
                        functionality.
5.7.2.4                 Galileo Local Element Augmented Availability Navigation                   Aviation would prefer to boost availability      Swiss
                        Functionality                                                             through the combined use of GPS and              Federal
                        A Galileo Local Element shall be developed to verify the                  Galileo instead of through Pseudolites.          Office for
                        provision of supplementary ‘pseudolite’ transmissions to improve                                                           Civil Aviation


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                        availability and/or accuracy, using as a basis the pertinent
                        requirements detailed in Section 3.4.2.4 of the MRD.
5.8.1.5                 Multipath                                                                 Again, coded multipath should also be             Swiss
                        Multipath requirements shall be detailed for the specific                 considered.                                       Federal
                        applications at system level to cover both ground and mobile                                                                Office for
                        carrier multipath.                                                                                                          Civil Aviation
6.14                    Recording & Archive Function                                              What exactly should be recorded, how              AENA
                        The system shall record the status of the Signals In Space (SIS)          often? How many global locations should
                        and archive this data for a minimum of 10 years (TBC).                    record?. What is the procedure to analyse
                        Remark: Should the SIS fall below specified standards, the                underperformance?. Please, clarify.
                        records can be investigated to assist in finding the cause of the
                        problem.
Annex 2A                Galileo Signal Design and Frequency Plan                                  Please, review the modulation type                AENA
                                                                                                  according to the outcome of the recent
                                                                                                  agreement with USA for signals #9 and #10.

                                                                                                  The Table should be updated in rows (9),          DFS
                                                                                                  (10), to reflect the decision to use BOC(1,1)
                                                                                                  modulation.
                                                                                                  It is recommended to evaluate how worse
                                                                                                  code tracking performance of the BOC(1,1)
                                                                                                  compared with the originally BOC(2,2)
                                                                                                  modulation will influence system
                                                                                                  performance or require reconfiguration in
                                                                                                  other areas (e.g. transmission power).

                                                                                                  This has been changed recently. E5a/b may         NATS UK
                                                                                                  be a continuous signal with two data
                                                                                                  messages on E5a and E5b. L1 will now be a
                                                                                                  BOC(1,1). This section needs a complete
                                                                                                  updating as it is totally out of date. The
                                                                                                  signals in E5A and E5B would be generated
                                                                                                  coherently, therefore giving the possibility to
                                                                                                  process them together for (1) increased
                                                                                                  accuracy, (2) redundancy (to mitigate


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                                                                                              interference from DMEs)." Even if E5a and
                                                                                              E5b were not coherently generated there
                                                                                              would still be a possibility to use the
                                                                                              redundancy between the two signals to cope
                                                                                              with DME interference. Also the use of L1
                                                                                              and E5b only has been considered.. Part (2)
                                                                                              of the requirement should be deleted as it is
                                                                                              an incorrect justification.
Annex 2A            A capability of encryption for integrity is envisaged and may be          This could only be accepted for security            STNA
Notes 6 & 10        activated pending results on potential market interest for integrity      purposes and should be totally
                                                                                              transparent to the aeronautical user on a
                                                                                              non discriminatory basis.
Annex 2B            SAFETY OF LIFE SERVICES                                                   The baseline signals that should be                 STNA
8.2                 SoL services may consider any of the signals {1,2,3,4,9,10}               considered for the performance assessment
                    combination, for instance:                                                are L1 and E5b for the safety of life service
                                                                                              and L1 and E5a for the open service. Else
                                                                                              the advantage of separating E5a and E5b
                                                                                              for redundancy wrt interference is lost.
Annex 2 B           Possibility to include commercial data is under assessment                This should not increase data rate in such a        STNA
Note 14                                                                                       way that it reduces significantly robustness
                                                                                              to interference.
Annex 3             Acronyms                                                                  ‘S’ in EGNOS stands for ‘Service’ instead of        AENA
                    EGNOS - European Geo-stationary Navigation Overlay System                 for ‘System’. please, amend.
Annex 4             DEFINITIONS                                                               Does this mean availability of service, or          NATS UK
10.5                Availability                                                              availability of integrity - two different things.
                    Availability is the percentage of time that at any location in the        Needs a better definition to clear up
                    coverage area, and at any time that both the accuracy and                 inconsistencies in document.
                    integrity requirements are met. During periods of non availability
                    the integrity requirements must still be met.                             There is no clear definition of Mean                STNA
                                                                                              availability whereas the only availability
                                                                                              figures are given as mean. Mean over
                                                                                              time, over space or over space and time.
Annex 4             DEFINITIONS                                                               Why is reacquisition time defined only for          Belgocontrol
10.7.5              Reacquisition time                                                        static receivers?
                    Time required for a static receiver to provide a valid 3D


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                    navigation within the limits shown after all satellite signals have       The TTF in reacquisition requirement should       STNA
                    been removed from the receiver. Continuous power is applied to            be specified for a user in dynamic conditions
                    the receiver during this test, but no commands or other                   which is the most likely case where a quick
                    information may be supplied. All the navigation parameters are            recovery after interference will be
                    known, clock drifts included but no integrity context. Tracking           necessary. The reacquisition is used mainly
                    loops are unlocked.                                                       for disruption of SIS reception due to
                                                                                              interference for example. In this case it
                                                                                              should not be considered that the receiver is
                                                                                              static but it should be considered as in the
                                                                                              worst dynamic conditions.
11.1.1.1            Galileo combined with GPS SPS - Signals                                   The baseline OS should be without E5b             STNA
                    The Galileo OS and SoL (mono frequency and dual frequencies)              and the baseline SoL should be without
                    services, combined with GPS SPS, shall be based on a                      E5a .
                    combination of frequencies shown in the following table.
Annex 6             Development of the Galileo Local Component                                We appreciate this paragraph, but would like      Swiss
12.3.2              Bearing in mind the context of Section 13.3, it is clearly                to note that for a Galileo Local Element to be    Federal
                    necessary to take steps to encourage the development of                   certified for Aviation use, significant amounts   Office for
                    Galileo Local Services in parallel to the development of the              of work, know-how build up and                    Civil Aviation
                    Global Component. Such measures have, and will continue to                infrastructure investments are necessary.
                    be taken throughout the development phase of Galileo by both              Despite various communications, the EC 6th
                    the EC as part of its 5th and 6th Framework activities, and ESA           Framework does not appear to share that
                    through the ‘GalileoSat’ program. Examples of such activities             view. In particular in the provision of all
                    include the definition of Local Element Architectures, the                weather landing operations, the timely
                    accommodation of Local Component in the overall system                    introduction of Galileo could be of
                    design (see Section 13.3.3), the modification of standards for            tremendous benefit to aviation (economy
                    Local Galileo operation, and the development and functional               and safety), but this work can only be
                    demonstrators to verify and demonstrate key aspects of Galileo            carried out if appropriately funded by FP6.
                    Local Service performance (see Section 5.7). All this is
                    undertaken with the understanding that, unlike with the Global
                    Services, there will exist throughout the development,
                    deployment and operation of Galileo, a continual scope for
                    innovation and change, and as such there is a need for flexibility
                    within the work.




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