[fitsbits] FITS standard for spatial planetary data

[Chiara Marmo]

Thanks for all your answers!

> From: "Rob Seaman" <seaman at noao.edu>
> > I am a Research Engineer in a French lab involved in Planetary Sciences
> > (surface imagery and spectro-imagery, in particular).
> 
> There are key issues in the data format, not just metadata. Do these images
> typically result from single chip/amplifier detectors? By spectra-imagery do
> you mean multi-channel spectrophotometry, or something more arcane? The
> answers to questions like this will inform whether raw and pipeline-reduced
> data should be formatted as 2-D or 3-D single images, as multiple extensions
> (MEFs), or possibly as FITS binary tables.

In general planetary surface images result from single (or mosaic of) drift-scan observations.
Spectra-imagery (often integral field spectrometer) produces cubes of drift-scans having wavelength as third dimension.

> Will any of these data be created onboard the spacecraft? Data compression
> for space missions may have requirements differing from those that have so
> far informed FITS tile compression. My suspicion is that the default Rice
> compression will be highly applicable here since it originally emerged from
> considerations of space-based data and operations paradigms, but it is
> possible that the noise regime of your data might drive some edge cases for
> tile compression.

I must admit that I never tried to apply tile compression to planetary data, and never thought about this problem... thanks for having highlighted it... I will check.

> 
> > Starting from Greisen & Calabretta 2002 and Calabretta & Greisen 2002,
> > projected images will be easily described: I will work with people from
> > PDS and PSA for consistent and unique definitions for each planet.
> 
> These are good partners to start with.  Are you aware of the PDS workshop
> series:
> 
> 	http://www.hou.usra.edu/meetings/planetdata2015/planetdata20151st.shtml
> 
> You might contact the Planetary Data Workshop folks.

Yep, we are in touch: US planetary missions have their own historical processing format and software (ISIS https://isis.astrogeology.usgs.gov/). FITS will be a plus and they are ready to collaborate on dictionaries about metadata.

> > 2) If not, is someone in this list interested in following or contributing
> > to this discussion?
> 
> I will be interested in FITS metadata (PDS-ready) for NEOs, asteroids and
> comets. One imagines there will be some amount of overlap.
> Presumably some of the metadata will correspond to planet-based timescales
> and a subgroup of us are embedded with timekeeping, FITS and otherwise.

I will keep it in mind! 

> > 3) Once a draft of a document is ready, to whom do I submit it? What is the
> > procedure for the IAU evaluates and accepts the new definitions?
> 
> As Steve says this is evolving, but the correct answer will continue to be a
> working group of the IAU Data and Documentation Commission, now dubbed C.B2.
> Several of us on FITSBITS are also on the OC for C.B2 and can help keep your
> effort moving forward through the vicissitudes of IAU restructuring.

So, as soon as I have something ready and accepted in the Europlanet working group I will send it to fitsbits list.

Thanks again!
See you soon (I hope)!

Chiara 

-- 
Chiara Marmo
Ingénieur de Recherche GEOPS - Paris Sud-11
Bât 509
Tel: +33 (0)1 69 15 49 03