1. IPDA Geometry Project Some Thoughts on What Next

2. Status as of July 2012 A Geometry Project team exists – But only NASA and ESA representation – Unknown if other agencies wanted, but could not afford to participate A draft white paper exists (Rev. 1, 4 July 2012) – Contains “requirements” (30) and “suggestions” (35), plus some questions and a fair amount of related discussion – Written by Acton; addresses some of the feedback recently received from team members – In principle is SPICE-agnostic, although it reflects much of the NAIF/SPICE paradigm To be consistent with current SPICE practice, most of the suggestions would have to be changed to requirements – Covers many topics; might omit some of interest to other team members – Generally written at a fairly high level; maybe ok, maybe not – Overall, it’s not fair to say it represents a complete and consensus view of the team

3. What follows are some thoughts on possible further actions. The IPDA SC might mix and match pieces as seems appropriate.

4. #1: Tidy Up and Terminate Spend small additional effort to tidy up the white paper, including adding in un- answered comments. Archive the white paper (also Simpson’s version thereof) within the IPDA for future reference. – SPICE continues to evolve within the PDS4 context. – PDS4 and IPDA continue their joint evolution. Any geometry-related issues that come up get addressed as needed, using whomever is interested and available, and however seems to make sense at that time. Referral could be made to the Geometry Project white paper. – Assume most or all agencies will continue using elements of SPICE as suits their interests, wallets and co-operation of NASA. – No real need to carry on with the Geometry Project. – The IPDA either endorses the white paper (when?, how?) or takes no official action with regard to ancillary data. In any case, SPICE does not become an IPDA standard. (Which is also the situation within PDS.) Also noted… – Assume there is not sufficient reason nor human and/or financial resources to establish any sort of sustained ancillary data working group. – NAIF continues to offer free standard SPICE user training in the U.S. Up to other agencies to organize anything beyond that (e.g. local training, production training).

5. #2: Carry On One More Year Try to broaden the participation, achieve substantial consensus (perhaps with some alternate opinions) and perhaps flesh out a bit more detail where needed. Somehow get some participation from at least JAXA, ISRO and RSA. Maybe also China or others? Continue development and refinement of the requirements and suggestions. As for the previous option, assume IPDA participating agencies are likely to continue using much of SPICE. At the end, the IPDA either endorses the white paper or takes no further official action. – In any case, SPICE does not become an IPDA standard. (Which is also the situation within PDS.) Also noted… Assume there is not sufficient reason nor human and/or financial resources to establish any sort of sustained ancillary data working group. NAIF continues to offer free standard SPICE user training in the U.S. Up to other agencies to organize anything beyond that (e.g. local training, production training).

6. #3: Form an Ancillary Data Working Group Terminate the Geometry Project; replace it with an enduring Ancillary Data Working Group under IPDA auspices that would work ancillary data issues of interest to the IPDA. How would it operate? How many agencies are likely to participate? (Seems there is a good chance there would not be sufficient interest or resources.) When start it up? (Maybe not right away?) Expected “products” and outcome of this WG are TBD.

7. #4: Adopt SPICE Adopt SPICE as the IPDA standard Retain the Geometry Project just long enough to revise the white paper – Change many suggestions to requirements, consistent with current NAIF/SPICE rules and practices – Obtain substantial consensus on the white paper – Seek to gain buy-in from currently non-participating agencies PDS4 and NAIF work out details related to ancillary data as needed Could try to form an enduring IPDA Ancillary Data Working Group – But see the points from the previous page.

8. Some Additional Points Some possible issues and questions no matter which direction is taken by the IPDA on “geometry” – Inadequate funding/interest in some agencies to do much – Do we try to deal with entities other than the ones already mentioned (NASA, ESA, RSA, ISRO, JAXA and maybe China Space Agency)? E.g. CNES, DLR, and other IPDA member organizations? – To the extent SPICE would be used, how would agencies/entities get needed training? – NASA is unlikely to back off from the use of SPICE – NAIF will continue to develop SPICE as it sees fit Up until now this has not seemed to conflict with users outside of NASA, but what if this should become at odds with an IPDA member, should the IPDA have more-or-less formally adopted SPICE?