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         Sectio Page Line     Comment                        Comment –                                                    Suggested Resolution –                                            Team Discussion                                   Status
                         n           #       Class –           Please describe your issue and the                                  Please propose a resolution to your                                                                                     (Open or
                                          Choose one                 basis for the comment.                                        comment including changes to text,                                                                                       closed)
                                            (Editorial,               Comments for MAIN BODY                                               where appropriate.
1       Goran Haslar    section           low low,            The information is irrelevant for the document organization.     Suggested resolution: delete Note 1                        Comment KK: rejected, this note has been added on           closed
           (=GH)         1.4.2               medium,          And also not appropriate in this kind of document                                                                           request of a group member. Reason: long discussions had
                                                                                                                                                                                          taken place on which technology is to be described.
                                              high)                                                                                                                                       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         Comment KK: not yet taken. We still believe that it is      closed
                         1.4.3                                that are used in the document                               that 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
        Rossiter                                              the architecture obscures relevant text.                                                                                    a colour printer nor on a black/white printer to see all text
        (=CR)                                                                                                                                                                             and the shading
5       G. Dunstone section 2.1           Editorial           The words 'transmission medium' do not distinguish between       Suggested resolution: Change all appearances of            Comment KK: done for version V0.8                               closed
           (=GD)                                              link technologies; e.g.: UAT & Mode S use 6the same band         'propagation medium' into 'link technology'
                                                              and medium
    6   CR             2,1                minor               Last line of paragraph 2: I would have interpreted               Change "propagation medium" to "datalink protocol".        Comment KK: see comment GD above. I believed solved             closed
                                                              "propagation medium" as the atmosphere for which we              Same comment also applies elsewhere within the             with the modification done in v0.8
                                                              cannot specify requirements.                                     document.
    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
                                                                                                                                                                                          should be made against the OSED for this application
                                                                                                                                                                                                                                                          to OSED
                                                                                                                                                                                                                                                          (done 27.9.)

    9   GH             section 2.2        low                 Add information that are beneficial for the surveillance, e.g.   Suggested resolution: add parameters that could improve    Comment KK: rejected. Copy from OSED. Comment has to            bring back
                                                              velocity, ground track and aircraft status                       the NRA application                                        be made against OSED
                                                                                                                                                                                                                                                          to OSED
                                                                                                                                                                                                                                                          (done 27.9.)

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 ATC processing system is considered vital for association
                                                                                                                              NOT 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           Suggested solution: delete                                 closed as per red lines 9-20-05.                                closed
                                             start 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             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
                       ??                 requirement         systems. Otherwise, you cannot distinguish them from DO-                                                    and added section reading ' A distinction
                                                              260 systems                                                                                                          between NUC and NIC/NAC/SIL airborne implementations
                                                                                                                                                                                   shall be provided by the Transmit Aircraft Domain. ANNEX
                                                                                                                                                                                   A, see below
17        Konrad       section            Missing explanation time of applicability ' is not explained and the requirement Suggested resolution: add definition and requirement in Comment KK: OPEN, need help of the group. PLaceholder                  closed
          Koebe        2.3.2              and requirement     how to calculate the 'absolute time' is missing              section 2.3.2                                           for 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                            closed
                                                              latency of ADS-B rebroadcast function                            rebroadcast system shall provide a time                    mtg
                                                              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                                                                      Comment KK: rejected: assumed vital for the proper              closed
                                             not believe that it is necessary to specify how the ground                                                                  functioning of the application. Even if it is recommendation
                                                              system 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
21      JBH            3.2.2              Medium                                                                               The Transmit Aircraft Domain shall, always transmit         Comment KK: similar comment received from G. Dunstone.         closed
                                                              Disagree with "The Transmit Aircraft Domain shall use the        barometric altitude when it is available and shall transmit Copied the text of GD into V0.8. IN addition section added
                                                              GNSS height only when barometric altitude is not available."     GNSS height when barometric altitude is unavailable. Both =>OK
                                                              It should be possible to transmit both with baro as a            barometric and geometric altitude may be transmitted
                                                              minimum                                                          simultaneously.
        JBH            3.2.2              Medium              more than 1 altitude may be sent: "The Transmit Aircraft                                                                     Comment KK: see comment above =>OK
                                                              Domain shall indicate which                                                                                                                                                                 closed
                                                              of the two altitude representations is provided in the ADS-B
                                                              message."                                                        :

                                                                                                                                                                                                                             Version 0.8
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             Closed
                                                                                                                                                                                       meeting. 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
                                                                                                                        *shall* not be used by aircraft implementations.               least
25   JBH         3.2.3                         Medium    text is superfluous: An HPL value of 1.0 NM also matches Substitute an appropriate reference.                                 Comment KK: not yet changed: Comment also received            closed
                                                        the presentation & draft paper by Stan Jones presented at                                                                      from GD, text GD taken, but Editorial remark added that
                                                        the RFG meeting in Miami titled “ADS-B Surveillance                                                                            comment shall be considered when rewriting the subsection.
                                                        Requirements to Support ATC Separation Standards” which                                                                        =>all considerations concerning the minimum value
                                                        argued that HPL(NIC) <1.0 Nm is adequate to support a 5                                                                        for HPL for NRA application, reference to SPR has
                                                        nm separation standard. It also stated “SIL = 2 (1*10 -5)                                                                      been inserted
                                                        risk level without an alarm require error bounds of NIC = 6
                                                        (0.5Nm) and NIC = 5 (1nm) for 3 NM and 5 NM separation
     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
                                                        "To allow the utilisation of ADS-B information for a variety of applications, the Transmit Domain shall XXcyclicallyXX                                                                       closed
                                                                                                                                                                                       OPA (5.1) gives requirement for update interval for quality
                                                        applications, the Transmit Domain shall cyclically              communicate accuracy and integrity indicators within an        indicators => refer to SPR
                                                        communicate accuracy and integrity indicators within an         ADS-B message
                                                        ADS-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 NUC/       Suggested resolution: after 'receiver' add 'or equivalent, or   Comment KK: added in section (new numbering) of CLOSED
                     3.2.3                              NIC values shall also allow DO-229c GPS receivers             DO-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 'may'
32   GH          section3.2.                   medium   If NUC is used alone it includes both, acccuracy and          Suggested resolution: there should be an explanatory text of Comment KK: tables from DO-242 and DO-242A added to       CLOSED
                    3                                   integrity information, but it does not explain how.           how NUC will fullfill the requirements for accuracy and      the 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       Replace "ADS-B data shall be useable for 5Nm separation " Comment KK:OPEN, see other comments on section 3.2.3 CLOSED
                                                        there 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-                                            copy from reference document)
                                                        requires selecting NUC based on HPL          C166 be adopted, i.e. for both technical
                                                        only and if HPL is unknown or un-            and trans-national reasons, it is highly
                                                        available, setting NUC=0.                    desirable to eliminate use of HFOM for
                                                                                                     encoding integrity.
4    A. Warren       18      SIL              The SIL table is different than that         Replace table with that in DO-242A.                                              During meeting table deleted again (only CLOSED
                                                        specified by DO-242A.                                                                                                         copy from reference document)
5    A. Warren       19                       Same issue in above                  Delete Note 1, consistent with TSO-                                                                                       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       provided by use of multi-sensor data, e.g.
                                                        years when the U.S. Air Force has            use of WAAS receivers or FMS/ INS
                                                        activated GPS spares as active satellites. backup to GPS during RAIM outages.
                                                        The Air Force only guarantees availability Depending on HFOM as a backup to HPL
                                                        of 24 satellites, not the 28 that are in the should not be used for Surveillance
                                                        constellation currently. In the Late 1990's where the consequences of an
                                                        there was a published incident with 7        undetected failure mode are Major level
                                                        Sats of bad geometry in which accuracy or greater. This statement should be
                                                        (HFOM) was O.K. based on best 4 Sats, replaced with a more generic statement
                                                        and HPL was very poor or unavailable.        on the value of having a backup source of
                                                        Such RAIM holes are rare today, but          position information to avoid loss of
                                                        recent RAIM outage rates are not a           continuity of position data for ADS-B.
                                                        reliable indicator of future values.

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

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

  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             Medium        A recommendation should be added to supervise multiple      Suggested Resolution- add a subsection with              Comment KK: added in V0.8                                     closed
                      section                         use of aircraft addresses                                   Recommendation: The ATC processing system should
                                                                                                                  include an algorithm to detect multiple aircraft using the
                                                                                                                  same aircraft address.
 39          GD         new             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
                      section                         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                Minor         A recommendation for additional ground system functionality Suggested Resolution- add a subsection 3.4.6 with              Comment KK: not yet taken, to be discussed during                  closed
                     section                          should be added                                             A. Recommendation : Additional ATC Processing meeting. Simple reason I do not understand the text
                                                                                                                  System 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 signals

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

41      KK           new                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
                                                      fact that it is not mandated to be provided by datalink in the
                     section                                                                                                                                                       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 Clarify                                                            ANNEX : corrected for V0.8                                       closed
                      A.                       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       Version number should be required for DO-260A compliant Suggested resolution: add a version requirement to section           Comment KK: v 0.8: sections A.1.3.10 and A. added         closed
copy                 ??                 requirement   systems. Otherwise, you cannot distinguish them from DO- 3                                                                   in Annex A
of 16                                                 260 systems

  8     A. Warren    A.     29                 There are also non-GPS sensors that                          add to the back end of this line "or an  accepted GNSS removed                                                                   closed
                                                      could qualify for NRA. This reviewer is                      alternative integrity containment metric
                                                      very uncomfortable with the exclusive use                    such as specified in DO-242A if the ADS-
                                                      of GPS language used throughout this                         B 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                              Same resolution as advised in                                   accepted NAC added in subsection                                 closed
                                                      encoding of accuracy metrics for                             comments.
                                                      position, i.e. NACp.
10      A. Warren    A.     30                 Need to add statement regarding                              Same resolution as advised in                                   a note has been added in ground velocity CLOSED
                                                      encoding of accuracy metric NACv for                         comments.                                                       part to indicate that velocity integrity
                                                      velocity, if available.                                                                                                      (NACv) is out of scope

                                                                                                                                                                                                                     Version 0.8

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