MINUTES OF THE P1J WORKSHOP 1-4 Oct 2002 The Fall 2002 P1J workshop was conducted at the Wyndham Greenspoint Hotel, Houston, Texas. A. PARTICIPANTS Chuck Acton (NASA/JPL), Alberto Cangahuala (NASA/JPL via telecon), Felipe Flores-Amaya (NASA/GSFC), Jacques Foliard (CNES), Joseph Guinn (NASA/JPL), Robert Kannenberg (NASA/GSFC/GST), Reinhard Kiehling (DLR), Mina Ogawa (NASDA), Siegmar Pallaschke (ESA/ESOC). B. AGENDA (See it at www.ccsds.org) C. NOTES ON ACTIVITIES Tuesday, 1 Oct 2002 * Review of Last Minutes: No issues came up; the minutes were accepted as is. * SpaceOps 2002: The EPM/OPM work was mentioned in Chuck Acton's paper "Extending NASAšs Spice Ancillary Information System to Meet Future Mission Needs." A poster of the EPM/OPM was displayed at the SpaceOps conference; and perhaps will be displayed at the ITC, too. Thanks to Chuck for this work. * On-board Timing Requirements: We agreed that discussions will continue with P1K until we understand all the issues. P1J will discuss prior to this week's joint session. Related to developing tracking data message. More details later. Future work includes attitude and tracking, and tracking has now taken higher priority. Urgency to have standard for tracking data, TSG and MC have expressed this desire. Rick Gavin, JSC, was invited to these meetings for one day, and we planned to talk more about tracking data issue after joint P1K meeting. JSC guys have worked these types of issues with Russians and ESA. * AIAA Standards for Astrodynamics: No status report this time. But we do want to ensure a good interface on navigation issues of mutual interest. Started discussion of all RIDs from the CCSDS agency-wide review. All RIDs were resolved. See responses to all RIDs at URL http://ccsds1.gsfc.nasa.gov/pub/ccsds/p1j/, file AgencyRIDs.zip GSFC RID 453/068-4, from P2 personnel, generated a long discussion about using XML, because it hasn't been adopted by CCSDS; PVL has been adopted, and yet P2 is now recommending XML. We should stick with our interim standard until XML is formalized. GSFC RID 453/068-2. AI-1, C. Acton and J. Guinn, to draft a para 2.3 addressing the concerns relating to OPM/EPM as discussed in the second para of the RID. Change will be made to section 3.5.1, d and e, and Table 4-3. GSFC RID 453-068-3. AI-2, R. Kiehling, to refine, make clearer, 3.1.2b material, but do that by creating a paragraph 2.4 with the reference material. 2.3 will be operational usage AI-3, C. Acton and J. Guinn, for part 2 in RID, move the RTN definition material to the Green Book. We'll simply reference the GB, e.g., "...or the RTN reference frame, which is described in reference [1]." 4.3 to say "reference frame", and then do "coordinate system" paragraph with a new 4. Also in 3.5.5.2d, change "coordinate frame" to "reference frame" - need to review for consistency. AI-4, S. Pallaschke, do text for 2.3 and 2.4, and then pass on to Chuck to take care of action re: ref frame vs. coord frame. AI-5, J. Guinn, to check Oliver Montebruck book to see how this issue, and the language, is handled/expressed in that doc. Then adopt that understanding of ref frame and coord sys for consistency. Make changes to GB. 1 p.m. Don Sawyer, Lou Reich, John Garrett (GSFC personnel from P2) joined us to talk about the PVL/XMl ref. Basis of lines vary among operating systems. Proposed that ODM use the CCSDS PVL language for the syntax and to allow other syntaxes in the future. Reorganize document to resolve issues, separating the syntax from the semantics. P2 offered to help doing this and to provide OPM example. P1J has a concern with a standard different than the current standard used by Mars Express and Rosetta, and other work with NASDA. But agreed to separate the semantics from the syntax, which may move to an annex. Changes will not impact international plans and readiness for promotion to BB. Chuck said JPL would be willing to work with ESOC if there is a need to change to PVL. AI-6, C. Acton, to make revision of syntax and semantics pertaining to issues on PVL and XML. Work with P2 personnel at GSFC. GSFC 453-068-5. Will discuss with P2 to get more details on SFDU format. Otherwise, same response as for P2 RID on PVL/XML. AI-7, S. Pallashcke, to make sections 3 and 4 consistent with 3 of this RID. Then provide input to Chuck. CRC RIDs. All changes will be made. Notes in RB will be reduced as part of the overall revision. Confirmed that Coordinated Universal Time (UTC) is the formal English version of this acronym, per IERS, Technical Note 21, so we'll go with that. Also commented that this ODM version is not the most efficient way to handle multiple vehicles, a corresponding version will be needed in the future. Wednesday, 2 Oct 2002 John Garrett (P2) attended beginning of meeting to present and explain XML example he created for ODM RB, as requested yesterday, so this AI is completed. P1J developed the ODM with emphasis on making it easy for humans to read, there is concern about having to make a quick change for PVL or XML, and the need to use browsers. P1J prefers to recommend staying with what we have, and issue the ODM RB in this way, but distinguish between the syntax and the semantics, thus leaving the door open to possibly go to XML later. ESOC RIDs. All changes will be made. AI-8, J. Guinn, to rewrite (d), p. 3-5, and move RTN material, p. 3-7, to GB. INPE RIDs. All changes will be made. We went over other verbal comments received from GSFC and ESOC. P2 concern about values in Table 3-2 will be corrected with the changes pertaining to P2 RID. Annex A, table A-1, line 2, will be revised. This concluded the review of all RIDs. We concluded that this review satisfactorily answered all the RIDs. Doc is not so different that we need another agency review. We need to incorporate RIDs and comments, as appropriate, take another internal look, and then present to the MC for promotion to BB. Regarding the PVL/XML issue, we plan to separate out the syntax, extend what we've done w/comments so that it becomes PVL-compliant w/out affecting current interfaces. Address XML later. In the syntax annex we could say that this Recommendation is PVL- compliant. Chuck accepted tech editing lead, then present doc to P1J for internal review, then to doc editor to be worked closely with P2 and tech editors. First draft due to panel mid-November, 11/15, then at least two weeks to review internally, and by end of Dec have it ready for MC approval. P3 rep, Gerhard Theis, arrived and asked for a joint P3/P1J mtg to discuss tracking issues and content of tracking messages. J. Guinn has a presentation that will probably answer those questions. Prelim set of reqs in Green Book. Agreed to meet with P3 next day. Summary of discussion on timing issues in preparation for joint session with P1K: What are timing issues assoc w/nav, and can we develop standard(s) related to the accuracy of timing, synchronization, distribution, and delay issues? We can simply add this material to the existing GB, to capture supporting material that would lead to a standard. Time as subset of tracking issue. Measurement tracking data has to be time-tagged. Some ancillary info goes along with calibration of those time tags. Is there some way to adjust those time tags to make them more correct? We can capture this info in the process started for the ephemeris messages, gather requirements first. Looked over "Phil Luer's material (GSFC/Code 561)." It reiterated lots of stuff from the GB. What about onboard timing or ground to ground timing requirements? Need to clarify where we can work together with P1K. First thing would be treatment of measurements, the time tagging, is no different than with anything else (e.g., camera picture, etc.) Second part is our ability to modify the time tagging. We can estimate what the offsets are. Calibration and Synchronization are two issues we may work w/P1K. What kind of onboard timing accuracy to we require? Calibration, synch and accuracy are issues we're interested in. Whose responsibility is it to deal with what issues? Is there a method to provide synchronization and calibration of the time tags? Unclear that creating a standard is currently a huge benefit, but there is a need to capture issues, so maybe adding to GB is the way to go. 1) synchronization (of clock on board) 2) calibration (time tags) 3) be clear about accuracy reqs for 1 and 2 4) ability to make corrections, uplink AI-9, J. Guinn, to write preliminary description of proposed new material on timing for GB and distribute to panel for review. This is not as critical as the ODM Red Book. Timing write-up from Joe due by Feb 1, and then panel will provide inputs within 30 days later, and then discussion at next meeting. GSFC P2 personnel return (D. Sawyer, L. Riech, J. Garrett): Felipe explains P1J conclusion about going forward now without PVL or XML, but splitting out the syntax into an annex, as P2 recommended. P2 wants to review the semantics section, considered the most important part. P1J and P2 accepted approach, with the understanding that we are not instituting PVL and/or XML compliance by allowing P2 input into the semantics section of the document. But Rec will easily adapt to PVL/XML formats. Chuck suggests that we could develop a PVL-compliant version 2, almost in parallel with first version. Summary of Tracking Data Discussion: Questions on tracking types and their corresponding prime items and corrections. Always run into problems with Doppler measurements within the ESA network. What is important to know if you perform a measurement? If you take a Doppler measurement, for example, you need to know aspect angle and spin rate, which you get from the telemetry. Create a table and from that devise appropriate tracking data messages commonalities. Suggestion to come up with a table is a good one. Section 6 of the GB, Measurements, can outline that. Timing and tracking are very related. Measurement part is a longer-term issue. Appendix B material of GB can include questions package dist earlier. And this time we'll suggest to P2 that they should start working with us early on. Do we need to expand on the GB we have? Do we put this material into the existing GB? Prioritize work so as to emphasize creation of Recs, as opposed to generating too many Green Books. AI-10, Al Cangahuala, to draft the first draft of a Tracking Data Green Book. To distribute to the Agencies for review prior to next meetings. Due this week. Future plan for generating a Recommendation for Attitude Messages: Attempt to do in parallel with Tracking Data. Jacques and Guillermo are lead. J. Foliard proposes to give one def for the quaternion. If we agree it's the only object for attitude, then the GB will be pretty short. For a Red Book, there are many solutions. Need to gauge the complexity/scope of the document. Need to decide on the applicable restrictions. We can come up with a list of reqs that drive this Attitude Product. J. Foliard says he has a matrix. AI-11, J. Foliard, to forward the Attitude Message matrix developed some meetings ago to the rest of P1J, NLT 60 days prior to Spring 2003. And write a draft of future doc for review at next mtg. Work with Guillermo to create it. Al Cangahuala called us: We talked about measurements discussion. Questionnaire on tracking went out. Al says he got questions about the questions. Al thinks next step would be to write a concept of operations paper, based on questionnaire. Concept of ops to describe how it will be used, and then Chuck thinks easy to write the reqs doc. Are we comfortable with a conops doc, as opposed to augmenting GB? Plan to keep it separate from the GB to facilitate Recommendation development. Al agreed to write a preliminary Ops Con doc, tonight or tomorrow, and forward it to the rest of the panel for review by their agencies. If we get no feedback, then let's proceed to create a Rec, which will have a CCSDS wide review. Is it premature to push the timing material into the GB, or should it be part of the Ops Con Doc that Al is going to write? Thursday, 3 Oct 2002 Summary of the joint P1J/P1K session: J. Guinn presented charts describing critical elements: time tags for measurements, onboard time, synchronization, calibration, correction, and accuracies. Primary objective for P1J, to identify definition of these elements to establish a standard for message exchange. P1J plans to add description of timing issues to the GB. C. Plummer (P1K) emphasized that what is not in place is a time management service, which is different for each spacecraft. P1K is interested in standard(s) pertaining to service interface/capability and error management. Summary of spacecraft ID requirements: AI-12, C. Acton, to write a WB on ID schema for all navigation objects: spacecraft, multiple-spacecraft, rovers, planets, landers, etc. Including list of questions generated previously. Due next week. Set of ID requirements to be formalized with P3. AI-13, all P1J, Determine whether CCSDS spacecraft ID doc needs to be updated. Summary of joint P1J/P3 session: P3 is interested in a tracking data service for scheduling and the elements pertaining to that service. Their space link extension (SLE) service includes a tracking data message format. P3 is looking for P1J to define the types of cross-support services for tracking data collection and processing; and needs to know what the message will be to make it easier for users to collect data. P1J will provide P3 with the concept of operations for tracking data and will work with them during the development of the tracking data standard. Next P1J completed the status report for the P1 plenary and discussed all action items. Friday, 4 Oct 2003 AI-14, Al Cangahuala and Mina Ogawa, to study the feedback collected from all agencies on the concept of operations provided by Al, to formulate a proposal for a standard, including on-line and off-line concepts. Then P1J will review the proposal for final determination. This work to be started following collection of feedback. Refer to AI-10. All info will be archived in the P1J web site. The process is to collect requirements, to define requirements, and to write material for a RB. Tuesday, 8 Oct 2003 Felipe presented the P1J activity report to the P1 Plenary. In response to the issues on timing a long discussion took place, but did not clarify how to resolve the question of the overall systems engineering scope. Creation of a working group was suggested. P1J will work with P1K to develop a concept of operations. The Fall 2002 P1J status report is available at the following URL. File name: P1JReport.ppt http://ccsds1.gsfc.nasa.gov/pub/ccsds/p1j/ D. Action Items New Action Items: All listed above. Old action items: P1J-S02-1) AI on P1J members: Have yourselves and colleagues review the current draft ODM Red Book (http://ccsds1.gsfc.nasa.gov/pub/ccsds/p1j/, file name ODM502- K.doc, and dated April 18, 2002). The idea here is to confirm that all the previously submitted RIDs were fairly addressed and that each agency accepts the P1J decision on these. Due: May 18. But if some further corrections are needed from this review, it will take some time to get e-mail concurrence on the proposed changes and then make these edits. So please complete this review ASAP and realize that all agencies will get another chance at review in the June 1 to September 1 cycle. CLOSED P1J-S02-2) Object ID. There are three action items relative to this issue. AI on Acton: Get caught up with and then nicely summarize for the rest of the Panel the characteristics, advantages and shortcomings of the various spacecraft ID systems now in use. Due May 18 CLOSED AI on Acton: Pass out the notes on spacecraft ID requirements and issues we made during our meeting. Due right after this ESOC meeting. (Done: Appendix A) AI on each agency: Write up a summary of current, local practices with regard to spacecraft IDs, and any known limitations/issues relative to any of the ID schemes we've talked about using. Answer all questions in Appendix A. Due: Response to be provided with the agency wide review. OPEN, REFER TO AI-12 ABOVE. Note: we did NOT propose to change the current Red Book at this point; we'll stick with the SpaceWarn ID for now even though many or all of us felt this was not a long=term viable answer. We noted that each agency can elect to use something else in any given planned use of the EPM/OPM. P1J-S02-3) AI on Acton: Include information about EPM/OPM in the paper for SpaceOps 2002. Due: Draft paper is due to SpaceOps organizers by May 15. CLOSED P1J-S02-4) AI on Acton: Write up a brief summary of testing of the EPM and send to Felipe. It is to be presented to the CCSDS meeting in September. Due: August 30. CLOSED Questions on the above: a) Is there also to be a report (by CNES and DLR) on testing of the OPM? It seemed that testing could not occur in time due to other commitments on the part of Reinhard. OPEN TBD b) Does the poster C. Acton will prepare (see below) replace the write-up, or is it in addition to the write-up? It's in addition. CLOSED P1J-S02-5) AI on Acton (lead) and Foliard: Prepare a poster for display at the CCSDS portion of SpaceOps 2002, in response to a request from each Panel for a "demo" of their results. Due: August 2002 CLOSED We talked about doing a demo of exchange/use of an EPM using two laptops, but felt this was too risky. (Maybe C. Acton would simulate this on his own laptop at the meeting, but there is NOT a commitment to do so.) This poster would serve in place of the demo. It would show in some fashion the use of EPM for Mars Express and Rosetta. And it would hopefully also show something about the trial use of OPM (that's Jacques contribution) if such is possible. P1J-S02-6) AI on all P1J members: Discuss with colleagues and then provide a recommendation whether or not to retain TCB as a valid time system in the ODM Red Book. Due: Not later than May 24. To be included --if a change is required--in the next version of the red book that is due out by May 30. OPEN. DUE: NOV 15 P1J-S02-7) Review papers from NASDA and ESOC on SLE tracking service. Material provided by S. Pallaschke. Also, refer to P1J- S2001-02 below. Assignee: All. Due: August 30. CLOSED P1J-S02-8) AI on P1J members: Review the current Navigation Green Book. It will be published as a new version with updates resulting from this review. Due: May 18. CLOSED Review of TSG and other action items: TSG-01-08 Use of XML: Still unclear on how it will help us solve our problems; Siegmar tried to arrange meeting with Nestor Peccia and Jenny Franks (during this Spring session) to understand which of our problems may be solved with XML. To be continued. CLOSED TSG-01-28 and TSG 01-29 Security: We agreed that our exchanges do not introduce drivers to the security requirements for our home institutions. We also discussed validity (the frequency of transmission errors and their impact, responsibility of checking the correctness of the file). Chuck Acton proposed adding a statement to the EPM/OPM Red Book that the generator of the message has indeed created a valid trajectory representation. Siegmar was also concerned about each agency making sure that they are using the latest version of each file (a delivery notification issue). We all agreed that this is at the edge of the sub-panel's charter. Acton asked if whether 'pushing or pulling' files should be factored in. Siegmar recommended that we ask the TSG how much we should be looking into this (this would be a large commitment of time). Jacques mentioned having a 'period of validity' for each file; Reinhard responded that this would not necessary help in these cases (like an emergency file delivery). Al mentioned that one would want a mechanism to 'turn off' the validity of the old file and 'turn on' the validity of a new file. Reinhard responded that this would take a lot of additional infrastructure. Questions for the network: What FTP validity checks are in place? What transmission error checks are in place? Felipe mentioned that he would bring up some of these issues at the Plenary meeting. To be continued. CLOSED. JOE GUINN OFFERED TO ADD WORDS TO APP A OF RB. Architecture: We're not sure what we're being asked for here; Felipe thinks it applies to how we provide services to each other. Siegmar thinks it applies to the common traits of our exchange formats. P1J-ESTEC-01: Incorporate S. Pallaschke's text into section 4.3.2.2. Assignee: F. Flores-Amaya Due Date: 1 December 2001. CLOSED (Words given to Felipe). P1J-ESTEC-02: Verify, validate, and renumber references in Green Book Assignee: F. Flores-Amaya Due Date: 1 December 2001. CLOSED (Wording in Green Book sufficient). P1J-ESTEC-03: Chuck Acton to distribute NAIF white paper on JPL use of quaternions. Guillermo Ortega to distribute similar technical notes. Assignee: C. Acton, G. Ortega Due Date: 1 December 2001. CLOSED P1J-ESTEC-04: Felipe Flores-Amaya to arrange a presentation of SPACEWARN's charter and procedures for maintaining their participant database to the panel. This could be arranged by videocon or telecon. Assignee: F. Flores-Amaya Due Date: 15 January 2002 CLOSED (Not needed based on discussion since last meeting). See new action item above. P1J-ESTEC-05: Chuck Acton to prepare requirements/proposal for a more complete participant ID system, possibly with SPACEWARN. Assignee: C. Acton Due Date: March 2002 CLOSED Replaced with new action item above. P1J-ESTEC-06: All panel members to check with home institutions about (i) consequences of making blanks and underscores significant or insignificant, (ii) need for defining a 'coordinate frame epoch' separate from the 'state vector epoch' in the OPM. Assignees: All Due Date: 15 December 2001. ((i) No problem (pending DLR check), (ii) Need more justification from agencies (GSFC, JPL especially) before having this word in either the OPM or EPM.) CLOSED P1J-ESTEC-07: Each agencies' representative to close out the Red Book RIDs covered this week upon receipt of an updated Red Book. Assignees: All Due Date: 15 January 2002. CLOSED (Completed by Red Book rewrite by Acton; agencies will have another opportunity to create new RIDs.) P1J-ESTEC-08: Propose schemes for extending OPM/EPM to accommodate multiple vehicles within one file. Assignees: All Due Date: March 2002 CLOSED (GSFC - Assign vehicle codes. SP - both, but I prefer 1 s/c per file. JF - Keep 1 s/c per data block. CA - It could be done, but what is the advantage? Let's propose that we keep the current Red Book to 'single spacecraft' until someone comes along and proposes a multiple-s/c use case.) P1J-ESTEC-09: SP to review interpolation issues related to the USABLE_START and STOP keyword definitions. Assignees: SP Due Date: 15 November 2001 CLOSED Response: (11/13) Siegmar contacted several colleagues from Flight Dynamics and the common opinion is that START_TIME and STOP_TIME should be maintained as mandatory keywords. The start-and stop- time is clearly defined by the first and last record of the ephemeris data. Any further information concerning proposed interpolation method and recommended reduction in time span should only be given as comments if the originator so wishes. The recommendation is not to include USABLE_START_TIME and USABLE_STOP_TIME as mandatory keywords. P1J-S2001-01 Meet or contact Damien Maeusli to discuss additional details for the objectives of the P1J/P1K joint meeting. Report results to P1J prior to the joint meeting on May 22. Assignee: G. Ortega Due date: CLOSED P1J-S2001-02: Collection of prioritized requirements and existing or proposed tracking data formats/messages, from each agency, for the development of a green and/or red book of recommendations for ground-to-ground tracking data. Also, answer all questions in Appendix B. Assignee: All (email information to other panel members) Due date: Aug 30, 2002 OPEN, REFER TO AI-14 ABOVE. P1J-Vilspa-1: Provide text for section 4.3.2.2, on planetary ephemeris reference system. Verify consistency in numbering of sections. Assignee: S. Pallaschke Due date: CLOSED. Felipe needs to incorporate the text into the Green Book (see P1J-ESTEC-01). P1J-Vilspa-7: Development of a red book of recommendations for attitude. Assignee: J. Foliard and G. Ortega Due date: July 2002 (first draft). CLOSED P1J-Vilspa-9: Development of a red book of recommendations pertaining to the exchange of navigation data for proximity operations. Flight to flight cases. (Ref. Joint panels 1A, 1B, 1E, 1J meeting Oct 2000.) Assignee: J. Guinn and G. Ortega (lead) Due date: Fall 2002 (See questions on 10 April). OPEN TBD P1J-Vilspa-10: Development of a red book for recommendations pertaining to the consistency in environmental models and astrodynamic constants. Assignee: J. Foliard and Al Due date: Fall 2002 (write up of ops concept questions). OPEN TBD ACKNOWLEDGEMENTS P1J members are pleased to express appreciation for the fine logistics provided by NASA during our Fall 2003 workshop; and special thanks to Chuck Acton and Bob Kannenberg for taking great notes during the week.