INTEROP-ADS-B-NRA Comment Form V08

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INTEROP-ADS-B-NRA Comment Form V08 Powered By Docstoc
					                                                             Comments to ADS-B                                                INTEROP V0.7                                                      15-Aug-05
                                                             Comments from                                                    INTEROP #2                                                        also included
#      Author Section Page Line          Comment                   Comment –                                                           Suggested Resolution –                                                     Team Discussion                                   Status
                             #            Class –    Please describe your issue and the basis                                     Please propose a resolution to your                                                                                              (Open or
                                        Choose one              for the comment.                                                  comment including changes to text,                                                                                                closed)
                                         (Editorial,        Comments for MAIN BODY                                                        where appropriate.
1    Goran Haslar     section          low                  The information is irrelevant for the document organization.      Suggested resolution: delete Note 1                              Comment KK: rejected, this note has been added on request      closed
        (=GH)          1.4.2                                And also not appropriate in this kind of document                                                                                  of a group member. Reason: long discussions had taken place
                                                                                                                                                                                               on which technology is to be described. Decision of the RFG
                                                                                                                                                                                               that only the globally agreed technology shall be described in
                                                                                                                                                                                               the INTEROP. Text added to represent that decision and avoid
                                                                                                                                                                                               repeated discussions.

2           GH        section          editorial            The list should only include the acronyms and abbreviations       Suggested resolution: remove the acronyms/abbreviations that Comment KK: not yet taken. We still believe that it is                closed
                       1.4.3                                that are used in the document                                     are not used in the document                                 advantageous to have a list of acronyms which frequently
                                                                                                                                                                                           appears in discussions of that subject. Naturally all which
                                                                                                                                                                                           appear in the document shall appear.
    3 J.Hammer      1.5                High                 References should include d DO-282A, DO-289.                      Add the appropriate reference                                Comment KK: not yet taken. DO-282 (UAT??) and DO-289                  closed
      (=JBH)                                                                                                                                                                               (ASAS?) are they really relevant for this application????

 4 Chris      2.1                      Improvement          IN figure 2-1, the shading used to highlight affected parts of    Remove the internal shading.                                 Comment KK: not done, as we have no problems neither on a
   Rossiter                                                 the architecture obscures relevant text.                                                                                       colour printer nor on a black/white printer to see all text and
   (=CR)                                                                                                                                                                                   the shading
5 G. Dunstone section 2.1              Editorial            The words 'transmission medium' do not distinguish between        Suggested resolution: Change all appearances of 'propagation Comment KK: done for version V0.8                                     closed
      (=GD)                                                 link technologies; e.g.: UAT & Mode S use 6the same band          medium' into 'link technology'
                                                            and medium
    6 CR            2.1                minor                Last line of paragraph 2: I would have interpreted "propagation   Change "propagation medium" to "datalink protocol".              Comment KK: see comment GD above. I believed solved with closed
                                                            medium" as the atmosphere for which we cannot specify             Same comment also applies elsewhere within the document.         the modification done in v0.8
    7 CR            2.1                minor                NOTE 1: Suggest changing the wording of "… does not               New wording: "…is not intended to imply a specific               Comment KK: changed in v0.8                                       closed
                                                            impose any architecture,".                                        architecture,"
    8 JBH           2.2                Minor                alerting list is incomplete                                       Add conflict alert and MSAW to the list                          Comment KK: I rejected that comment as this comment               bring back to
                                                                                                                                                                                               should be made against the OSED for this application
                                                                                                                                                                                                                                                                 OSED (done

    9 GH            section 2.2        low                  Add information that are beneficial for the surveillance, e.g.    Suggested resolution: add parameters that could improve the      Comment KK: rejected. Copy from OSED. Comment has to              bring back to
                                                            velocity, ground track and aircraft status                        NRA application                                                  be made against OSED
                                                                                                                                                                                                                                                                 OSED (done

10 CR               2.3                minor                In the information list, the 24 bit address is repeated on each   Remove the reference to the 24 bit address from the second        Comment KK: rejected. The 24bit in all info transferred to the   closed
                                                            bullet.                                                           and third bullets. This is section is identifying information NOT ATC processing system is considered vital for association
                                                                                                                              messages.                                                         tasks; in addition this is copied from OPA

11 JBH              2.3.1              low                  last S 1st P does not make sense.                                 correct it                                                       Comment KK: Improvement attempted in V0.8                         closed
12          GD      section            Editorial            The concept of defining when the receive system should start      Suggested solution: delete                                       closed as per red lines 9-20-05.                                  closed
                                           composing is unnecessary
13 CR                 minor                There is a word missing after "ADS-B".                            Change "ADS-B" to "ADS-B reports"                                Comment KK: done in v0.8                                          closed
14 Chris              minor                Change "shall" to "should" - this is a recommendation.                                                                             Comment KK: see comment above - done in V0.8                      closed
15      GD          section            Editorial            is done' can be better expressed                                  Suggested solution: update text                                  Comment KK: text of section updated to contain a          closed
                                                                                                                                                                              'should'; Second sentence set into different subsection
                                                                                                                                                                                               (contains 'shall').
16    Don Walker section???            Missing requirement Version number should be required for DO-260A compliant            Suggested resolution: add a version requirement to section 3     Comment KK: Main Body resolved by Note in section         closed
                 ??                                        systems. Otherwise, you cannot distinguish them from DO-                                                                            and added section reading ' A distinction between
                                                           260 systems                                                                                                                         NUC and NIC/NAC/SIL airborne implementations shall be
                                                                                                                                                                                               provided by the Transmit Aircraft Domain. ANNEX A, see
17      Konrad      section            Missing explanation time of applicability ' is not explained and the requirement how Suggested resolution: add definition and requirement in            Comment KK: OPEN, need help of the group. PLaceholder for         closed
        Koebe       2.3.2              and requirement     to calculate the 'absolute time' is missing                      section 2.3.2                                                      note in section and new section added in V0.8
                                                                                                                                                                                               (to be filled) text changed per september meeting

 2   A. Warren      2.3.2         14                        Need to add statement regarding max                               Add new statement "The ADS-B                             agreed to changed text per september mtg                          closed
                                                            latency of ADS-B rebroadcast function                             rebroadcast system shall provide a time
                                                            when applicable.                                                  stamp on re-broadcast, or shall transmit
                                                                                                                              ADS-B received messages within TBD
                                                                                                                              seconds of message reception.
18          GD      section 3.1        Editorial            Separate out the different identification types into a), b),c).   Suggested solution: change text                                  Comment KK: disagree. We are on ground in this section,           closed
                                                            Mode A is optional. The different propagation medium is not                                                                        here the and/or is taken from the OSED. It is optional in
                                                            appropriate since the whole document applies to all                                                                                messages, but not in the ground requirement
19          GD        section          Minor                A note should be added to indicate that aircraft address is       Suggested Resolution- add Note : Typically the aircraft          Comment KK : added to V0.8                                        closed
                                           used to associate ADS-B reports to each other                     address is used to link a new ADS-B report to
                                                                                                                               existing internal surveillance information (e.g. track).

20 CR                 minor                These two requirements should be recommendations. I do not                                                                         Comment KK: rejected: assumed vital for the proper                closed
                                           believe that it is necessary to specify how the ground system                                                                      functioning of the application. Even if it is recommendation
                                                            correlates reports with its own internal data. The two                                                                             with should it has to be 2 sentences.
                                                            paragraphs could be combined into one with the
                                                            recommendation that the ground system use the identification
                                                            elements in a specific order to do its data correlation.

21 JBH              3.2.2              Medium                                                                                 The Transmit Aircraft Domain shall, always transmit              Comment KK: similar comment received from G. Dunstone.            closed
                                                                                                                                barometric altitude when it is available and shall transmit    Copied the text of GD into V0.8. IN addition section added
                                                            Disagree with "The Transmit Aircraft Domain shall use the         GNSS height when barometric altitude is unavailable. Both        =>OK
                                                             GNSS height only when barometric altitude is not available."     barometric and geometric altitude may be transmitted
                                                            It should be possible to transmit both with baro as a minimum     simultaneously.

                                                                                                                                                                                                  Version 0.8
22 JBH          3.2.2                          Medium   more than 1 altitude may be sent: "The Transmit Aircraft                                                                         Comment KK: see comment above =>OK                              closed
                                                        Domain shall indicate which
                                                        of the two altitude representations is provided in the ADS-B
                                                        message."                                                         :
23 JBH          3.2.2                          Medium    title of section is inaccurate                                   Should be: "Altitude"                                          Comment KK: I rejected that comment as I have used the          closed
                                                                                                                                                                                         parameter names used in the OSED and OPA for the
                                                                                                                                                                                         application => title changed from baro altitude to baro
                                                                                                                                                                                         altitude or geo height
24 JBH / CM     3.2.2                          Medium   recommendation should be a shall                                                                                                 Comment KK: not yet taken, to be discussed during meeting.      Closed
                                                                                                                                                                                         GD also addresses that problem. BUT: OPA (6.2) requires
                                                                                                                                                                                         only > or = 100ft which seems to allow for GILHAM
                                                                                                                           Altitude data which are Gilham encoded (100ft increment)      =>rejected as 100 ft increment is permitted for GA at least
                                                                                                                          *shall* not be used by aircraft implementations.
25 JBH          3.2.3                          Medium    text is superfluous: An HPL value of 1.0 NM also matches the Substitute an appropriate reference.                               Comment KK: not yet changed: Comment also received from         closed
                                                        presentation & draft paper by Stan Jones presented at the                                                                        GD, text GD taken, but Editorial remark added that comment
                                                        RFG meeting in Miami titled “ADS-B Surveillance                                                                                  shall be considered when rewriting the subsection. =>all
                                                        Requirements to Support ATC Separation Standards” which                                                                          considerations concerning the minimum value for HPL for
                                                        argued that HPL(NIC) <1.0 Nm is adequate to support a 5 nm                                                                       NRA application, reference to SPR has been inserted
                                                        separation standard. It also stated “SIL = 2 (1*10 -5) risk level
                                                        without an alarm require error bounds of NIC = 6 (0.5Nm) and
                                                        NIC = 5 (1nm) for 3 NM and 5 NM separation respectively.

26 JBH          3.2.3                          Medium   No reason for this to be required to be cyclic:                   To allow the utilisation of ADS-B information for a variety of Comment KK: 'cyclically' deleted in V0.8. But note that the     closed
                                                        "To allow the utilisation of ADS-B information for a variety of   applications, the Transmit Domain shall XXcyclicallyXX         OPA (5.1) gives requirement for update interval for quality
                                                        applications, the Transmit Domain shall cyclically                communicate accuracy and integrity indicators within an ADS- indicators => refer to SPR
                                                        communicate accuracy and integrity indicators within an ADS-      B message
                                                        B message"
27 GD            section3.2.                            In 2nd par. behind note, and shall be replaced by and/or as       Suggested resolution: change to 'and/or'                       Comment KK: partially done in V0.8. Only retained the 'and'  closed
                           3                            sometimes it may only be NUC which is available                                                                                  as 'or' may give the impression that one of the items may be
                                                                                                                                                                                         omitted, which is not the case (they can be combined) =>part
                                                                                                                                                                                         completely changed, comment agreed

28 GD               section                                                                                               use subsection numbers for requirements and                       Comment KK: subsection numbering implemented in V0.8             CLOSED
                      3.2.3                                                                                               recommendations .                                                 ( to and to, for a later comment
                                                                                                                                                                                            a section added additionally =>editorial will be
                                                                                                                                                                                            reviewed separately
29 GD               section                             add design requirement to use HPL                                 Suggested resolution: text proposed by GD                         Comment KK: text proposed by GD implemented as           CLOSED
                      3.2.3                                                                                                                                                                 and Note following the paragraph.
30 GD               section                             The recommendation concerning the determination of                Suggested resolution: after 'receiver' add 'or equivalent, or DO- Comment KK: added in section (new numbering) of          CLOSED
                      3.2.3                             NUC/NIC values shall also allow DO-229c GPS receivers             229c GNSS receiver'                                               V0.8

31 GD               section                             the description should be changed into a 'positive sense'         Suggested resolution: new text proposed                        Comment KK: I have copied the text as modified by GD into     CLOSED
                      3.2.3                                                                                                                                                              the document, without numbering it yet. There are NO 'shalls'
                                                                                                                                                                                         in his text, I doubt that we can formulate requirements with
32 GH            section3.2.                   medium   If NUC is used alone it includes both, acccuracy and integrity    Suggested resolution: there should be an explanatory text of   Comment KK: tables from DO-242 and DO-242A added to the CLOSED
                           3                            information, but it does not explain how.                         how NUC will fullfill the requirements for accuracy and        main body with explanatory text. During meeting SG decided
                                                                                                                                                                                         to delete the tables again (copy of reference document only)

33 CR           3.2.3                          minor    There is a requirement on ADS-B here where I think that there Replace "ADS-B data shall be useable for 5Nm separation "          Comment KK:OPEN, see other comments on section 3.2.3            CLOSED
                                                        should be a statement of intent.                              with                                                               when addressing this comment. During meeeting 3.2.3
                                                                                                                      "ADS-B data is useable for 5Nm separation"                         completely rewritten.

                                                                                                                          Add a separate requirement to state that the ground system
                                                                                                                          shall not use ADS-B data with an HPL value of less than TBD
                                                                                                                          for 5NM separation.
3   A. Warren        16-17   NUC              The NUC table is not consistent with TSO-      For international interoperability, suggest    During meeting table deleted again (only                                                           CLOSED
                                                        C166 Appendix 1, section (1.2) that            that the more strict standard in TSO-C166 copy from reference document)
                                                        requires selecting NUC based on HPL only       be adopted, i.e. for both technical and trans-
                                                        and if HPL is unknown or un-available,         national reasons, it is highly desirable to
                                                        setting NUC=0.                                 eliminate use of HFOM for encoding
4   A. Warren        18      SIL              The SIL table is different than that specified Replace table with that in DO-242A.            During meeting table deleted again (only                                                           CLOSED
                                                        by DO-242A.                                                                                   copy from reference document)
5   A. Warren        19                       Same issue in above                    Delete Note 1, consistent with TSO-C166.                                                                                                          closed

6   A. Warren        19                       Evidence that HFOM is O.K. cannot be                              Appropriate back-up of HPL should be                                                                                           closed
                                                        based on data obtained in the last few years                      provided by use of multi-sensor data, e.g.
                                                        when the U.S. Air Force has activated GPS                         use of WAAS receivers or FMS/ INS
                                                        spares as active satellites. The Air Force                        backup to GPS during RAIM outages.
                                                        only guarantees availability of 24 satellites,                    Depending on HFOM as a backup to HPL
                                                        not the 28 that are in the constellation                          should not be used for Surveillance where
                                                        currently. In the Late 1990's there was a                         the consequences of an undetected failure
                                                        published incident with 7 Sats of bad                             mode are Major level or greater. This
                                                        geometry in which accuracy (HFOM) was                             statement should be replaced with a more
                                                        O.K. based on best 4 Sats, and HPL was                            generic statement on the value of having a
                                                        very poor or unavailable. Such RAIM holes                         backup source of position information to
                                                        are rare today, but recent RAIM outage                            avoid loss of continuity of position data for
                                                        rates are not a reliable indicator of future                      ADS-B.

                                                                                                                                                                                            Version 0.8
     7   A. Warren       19                        One of the main reasons for approving DO-                          Delete the statement beginning "In the                                                                                            closed
                                                               242A was to tighten up on the standards for                        absence of HPL, …". If a particular state
                                                               integrity assessment. The use of HFOM for                          wants to adopt a weaker criterion than that
                                                               encoding NUC was felt by SC-186                                    of the international standard, there is
                                                               committee to be a bad practice, since the                          nothing preventing them from doing so.
                                                               receiver cannot tell whether NUC is an                             The international standards for NRA should
                                                               accuracy or integrity parameter. If we use                         be based on DO-242A and consistent with
                                                               FMS or non-GPS based navigation                                    current best practices. These standards,
                                                               solutions as a backup, then there is no                            such as DO-289 call out the use of NIC and
                                                               generally usable relationship between                              NACp values for each ADS-B application.
                                                               accuracy metrics (EPU) and containment                             The compromise adopted in TSO-C166 to
                                                               radius (Rc). The receiver of ADS-B data will                       use legacy DO-260 equipment is as far as
                                                               not be able to tell whether the source of                          the international community should go in
                                                               NIC/NUC is a GPS sensor or not.                                    accomodating existing equipment.

 34 GD                     section                             I disagree with the comment that ICAO sets a requirement for       Suggested resolution: change text                               Comment KK: I have not taken this advise. The text does not closed
                             3.3.1                             systems in the referenced Annex 22. Interestingly, maybe                                                                           say that there is a system requirement. An ATS requirement is
                                                               Annex 11 will need to add more once ADS-B is used!                                                                                 cited which is to be taken over for the NRA application - and
                                                                                                                                                                                                  that is as per OSED.
 35 GD                     section                             The distinct indicators need to be used by the ATM system -        Suggested resolution: change text                               Comment KK: I have not taken that over. I believe that all what closed
                                              but this can only occur if they are received. Some aircraft will                                                                   is commented here is addressed in the preceding sections.
                                                               transmit the distinct indicators and others will (not).

 36 GD                 section 3.4                             A number of ground requirements have already been listed           Suggested resolution: add 'other' to the title of the section   Comment KK: done for V0.8, but renumbered to 3.5 due to           closed
                                                                                                                                                                                                  insertion of another section
 37 JBH               All section         Minor                See red-lined copy for editorial changes                                                                                           Comment KK: editorials incorporated into V0.8, but 'area' not     closed
                                                                                                                                                                                                  changed into 'airspace' as CASCADE programme description
                                                                                                                                                                                                  says 'area' and changes in rejected as it is understood
                                                                                                                                                                                                  that not all implementation are capable to do more than the
                                                                                                                                                                                                  general emergency indication.
38            GD      new section         Medium               A recommendation should be added to supervise multiple use Suggested Resolution- add a subsection with                     Comment KK: added in V0.8                                         closed
                                                               of aircraft addresses                                       Recommendation: The ATC processing system should
                                                                                                                           include an algorithm to detect multiple aircraft using the same
                                                                                                                           aircraft address.
39            GD      new section         Medium               A recommendation should be added to supervise clearance     Suggested Resolution- add a subsection 3.4.5 with                Comment KK: added to V0.8                                               closed
                                                               adherence                                                   Recommendation: The ATC Processing System should
                                                                                                                           contain a monitoring function to detect mismatches between
                                                                                                                           the ATC clearance and ADS-B reported altitude.
40       GD           new section         Minor                A recommendation for additional ground system functionality Suggested Resolution- add a subsection 3.4.6 with A. Comment KK: not yet taken, to be discussed during meeting.                  closed
                                                               should be added                                             Recommendation : Additional ATC Processing System                Simple reason I do not understand the text
                                                                                                                           functionality described below can be provided to improve the
                                                                                                                           integrity of downlinked positional data, providing additional
                                                                                                                           protection against GNSS faults :
                                                                                                                           a) Implement functionality which uses signals from site
                                                                                                                           monitors to allow GNSS parameters to be monitored and for
                                                                                                                           ATC to be provided warnings regarding GNSS satellite
                                                                                                                           problems. Functionality that can be provided includes :
                                                                                                                           Ø Monitor the position reported by the site monitor compared
                                                                                                                           to the surveyed position
                                                                                                                           Ø Monitor the HPL reported by site monitors
                                                                                                                           Ø Monitor the site monitor GNSS receiver ‘s “Fault detection
                                                                                                                           and exclusion” status to provide early warning of faulty ranging

                                                                                                                                  b) Provide ATC users with predictions of inadequate HPL
                                                                                                                                  based upon GNSS satellite geometry, current satellite status
                                                                                                                                  and US Government NANUs.

41       KK           new section         Minor                Ground velocity is addressed in the AnneX A. In spite of the       4 renumbered to 3.5                                             Comment KK: section 3.4 created in main body, old section         CLOSED
                                                               fact that it is not mandated to be provided by datalink in the                                                                     3.4 renumbered to 3.5
                                                               OSED, an insert should be made in the main body to justify
                                                               Comments for ANNEX A
 42 JBH               ANNEX               High                 Sections A1.2.1.1 and A1.2.1.2 are very confusing. It is not       Clarify                                                         the definition of a) and b) has been added to clarify, and the    closed
                                              clear what is being referred to as "definition case a or b."                                                                       sentence has been changed. See v0.72 or v0.8

43       Tom Mosher    ANNEX              Medium              There seems to be a discrepancy regarding the use of Mode A Clarify                                                                 ANNEX : corrected for V0.8                                        closed
                       A.                              codes. Section creates a requirement to transmit the
                                                              Mode A code, if it is available and a message format exists to
                                                              represent it. However, Annex A. says in a Note that
                                                              transmitting the Mode A is optional
         Don Walker section???            Missing requirement Version number should be required for DO-260A compliant        Suggested resolution: add a version requirement to section 3         Comment KK: v 0.8: sections A.1.3.10 and A. added          closed
copy                ??                                        systems. Otherwise, you cannot distinguish them from DO-                                                                            in Annex A
 of                                                           260 systems
     8   A. Warren    A.      29                        There are also non-GPS sensors that could                          add to the back end of this line "or an   accepted GNSS removed                                                                   closed
                                                               qualify for NRA. This reviewer is very                             alternative integrity containment metric
                                                               uncomfortable with the exclusive use of                            such as specified in DO-242A if the ADS-B
                                                               GPS language used throughout this                                  data source is not a GNSS sensor."
                                                               document, e.g. the use of HPL instead of
                                                               containment radius (Rc).
     9   A. Warren    A.      29                        NEED to add statement regarding encoding                           Same resolution as advised in comments.                         accepted NAC added in subsection                                  closed
                                                               of accuracy metrics for position, i.e. NACp.

10       A. Warren    A.      30                        Need to add statement regarding encoding                           Same resolution as advised in comments.                         a note has been added in ground velocity        CLOSED
                                                               of accuracy metric NACv for velocity, if                                                                                           part to indicate that velocity integrity (NACv)
                                                               available.                                                                                                                         is out of scope

                                                                                                                                                                                                    Version 0.8

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