Lightcurve datamodel?

Mireille LOUYS mireille.louys at unistra.fr
Fri Jun 14 19:03:07 CEST 2024


Hi Mark ,
Yes it was a work in progress at the time of Obscore1.1 publishing and 
has not been finalized as a note .
Implementation feedback is needed.

The point is that we have focused much of our VO efforts in building 
metadata for VOTable format and less on the crosswalk tasks
between various FITS metadata encoding and TAP.

Thanks, Mireille

Le 14/06/2024 à 18:16, CresitelloDittmar, Mark a écrit :
> Thanks Mireille,
>    This is not included in the ObsCore1.1 standard.. right?  Does it 
> exist anywhere official/semi-official that we can reference?
>
> Also.. I wanted to pass along a ping I got from Tess Jaffe on the 
> subject..
> Basically a reminder that the OGIP FITS standards cover these sorts of 
> data (including light curves) and should be folded into any IVOA Note 
> suggesting FITS serializations of such products.
>     * https://heasarc.gsfc.nasa.gov/docs/heasarc/ofwg/ofwg_recomm.html
>     * 
> https://heasarc.gsfc.nasa.gov/docs/heasarc/ofwg/docs/rates/ogip_93_003/ogip_93_003.html 
>
>
> Mark
>
>
> On Fri, Jun 14, 2024 at 10:53 AM Mireille LOUYS via dm <dm at ivoa.net> 
> wrote:
>
>     Hi Kelle, Mark,
>     Hi Igor,
>     Hi DMers ,
>
>
>     In the revision of Obscore 1.1 , I did provide a mapping for
>     ObsCore attributes to FITS keywords for the Binospec project .
>     That was a request from Igor Chilingarian to map the data produced
>     to ObsCore seemlessly.
>
>     I don't know today what has been used in the archive , but Igor
>     may help to correct and give feedback.
>
>     Here attached is the first mapping table proposed .
>     The Time extension for ObsCore is not covered yet  in this table.
>
>     Eager to help for this ,
>     Best regards , Mireille
>
>     Le 13/06/2024 à 21:17, CresitelloDittmar, Mark via dm a écrit :
>>     Sweet!
>>     I do think that would be very handy for providers just now
>>     defining their products.
>>
>>     The Notes are pretty open contributions..
>>     The first step would be to create a repository for it at:
>>     https://github.com/ivoa
>>     If you go there, you'd see the HEIG Note repo as a good/recent
>>     addition example.
>>
>>     I would be able to create the repo, but don't have the time (at
>>     least not today) to put together the document framework.
>>     Mark
>>
>>
>>
>>     On Thu, Jun 13, 2024 at 3:00 PM Kelle Cruz <kellecruz at gmail.com>
>>     wrote:
>>
>>         I would be happy with an IVOA Note for FITS serializations!
>>
>>         And yes, it could also list multiple keywords that are in use
>>         for various concepts.  And this oldie but goodie list of
>>         Commonly Used FITS keywords can also serve as inspiration. I
>>         note that this document also includes a reference to which
>>         institution initially adopted it/defined it.
>>
>>         How does one go about writing an IVOA Note? As you can tell,
>>         I'm eager to contribute.
>>
>>         Kelle
>>
>>         On Thu, Jun 13, 2024 at 2:47 PM CresitelloDittmar, Mark
>>         <mdittmar at cfa.harvard.edu> wrote:
>>
>>             Kelle,
>>
>>             For quick reference, this PDF came from:
>>             https://wiki.ivoa.net/twiki/bin/view/IVOA/ImageDM
>>             That's along the lines of what I meant..
>>
>>             Optimally, I think this is best provided as an IVOA Note
>>             for FITS serializations (rather than within an ObsCore
>>             level standard), that could somehow consolidate the model
>>             concepts which are repeated in some of these early
>>             models, and suggest a FITS name for it.   If done well,
>>             it would track down and integrate existing dictionaries
>>             like the MAST one you point to in the Issue
>>             (https://outerspace.stsci.edu/display/MASTDOCS/Light-curve+Metadata).
>>
>>             Mark
>>
>>
>>
>>
>>             On Thu, Jun 13, 2024 at 2:22 PM Kelle Cruz
>>             <kellecruz at gmail.com> wrote:
>>
>>                 I also found this PDF which is SUPER USEFUL!  It
>>                 seems to be part of the idle ImageDM project. Is
>>                 there any reason not to use this table as a guide?
>>
>>                 btw, I'm updating the table in the issue as I figure
>>                 things out:
>>                 https://github.com/ivoa-std/ObscoreTimeExtension/issues/8
>>
>>                 Thanks,
>>                 Kelle
>>
>>                 On Thu, Jun 13, 2024 at 12:41 PM Kelle Cruz
>>                 <kellecruz at gmail.com> wrote:
>>
>>                     What if instead of saying “standard” keywords, we
>>                     call them “suggested“ and make the table an
>>                     appendix?  That way, we’re not saying people need
>>                     to “recast” their FITS files, but we are
>>                     providing useful information for folks generating
>>                     new data products?
>>
>>                     There’s a real opportunity here to make it easier
>>                     for the “common” astronomer to implement and
>>                     adopt VO-type concepts and methods which improve
>>                     data accessibility and reusability. Providing
>>                     FITS keyword suggestions is immediately useful to
>>                     lots of folks and would be seen as a positive
>>                     benefit of the VO.
>>
>>                     kelle (via iOS)
>>
>>
>>                     On Thu, Jun 13, 2024 at 12:24 PM
>>                     CresitelloDittmar, Mark
>>                     <mdittmar at cfa.harvard.edu> wrote:
>>
>>                         Kelle,
>>
>>                         Regarding the issue you posted on the
>>                         ObsCoreTimeExtension repo.
>>                         https://github.com/ivoa-std/ObscoreTimeExtension/issues/8
>>
>>                         I thought you might hit this problem since
>>                         you're looking for standard FITS keywords for
>>                         your lightcurves.
>>                         The ObsCore standard (and extensions) are
>>                         targeted toward Data Discovery threads, which
>>                         pass the information around in VOTables
>>                         annotated with UTypes.
>>                         As such, that probably isn't a good place to
>>                         put corresponding FITS keywords.
>>
>>                         There are very few models targeting Data
>>                         Products, and even there, I think only
>>                         Spectrum includes FITS serialization specs. 
>>                         In general, the data models should be
>>                         independent of serialization standards, and
>>                         that is the direction we have been moving
>>                         towards in the newer, vo-dml compliant models.
>>
>>                         It sounds like what you are looking for is a
>>                         mapping from the ObsCore (and extension)
>>                         UTypes to a VO recommended FITS keyword..
>>                         which I don't believe exists other than what
>>                         is defined in Spectrum.  Or perhaps
>>                         preferably a FITS serialization standard
>>                         which maps model concepts to FITS key/column
>>                         specs... which certainly doesn't exist in the VO.
>>
>>                         I think the idea has been:
>>                           * Everybody uses different FITS keywords to
>>                         serialize their data
>>                           * We need to standardize something for Data
>>                         Discovery that doesn't force everyone to
>>                         recast their FITS files
>>                           * So we'll communicate in VOTable and tag
>>                         the concepts with UTypes
>>                               + data providers can then map their
>>                         individual keywords to the ObsCore standard
>>                         UTypes.
>>
>>                         I'm afraid this isn't a very encouraging
>>                         email.. I'm not sure what to recommend for you.
>>                         Anyone.. Please correct me if I've missed a
>>                         resource that would be helpful here.
>>
>>                         Mark
>>
>>
>>
>>
>>
>>                         On Wed, Jun 12, 2024 at 8:28 AM Kelle Cruz
>>                         via dm <dm at ivoa.net> wrote:
>>
>>                             This document has what I’m looking for! 
>>                             Thanks everyone.
>>
>>                             https://github.com/ivoa-std/ObscoreTimeExtension/blob/master/ObscoreTimeExtension.pdf
>>
>>                             kelle (via iOS)
>>
>>
>>                             On Wed, Jun 12, 2024 at 3:59 AM BONNAREL
>>                             FRANCOIS
>>                             <francois.bonnarel at astro.unistra.fr> wrote:
>>
>>                                 Hi,
>>
>>                                 Ada and I wrote in parallel, but we
>>                                 are pointing to the same IVOA note !
>>
>>                                 Best regards
>>
>>                                 François
>>
>>                                 Le 12/06/2024 à 09:57, NEBOT
>>                                 GOMEZ-MORAN Ada (OBS) via dm a écrit :
>>                                 > Hi Kelle,
>>                                 >
>>                                 > we wrote this note some time ago:
>>                                 >
>>                                 >
>>                                 https://www.ivoa.net/documents/Notes/LightCurveTimeSeries/20231122/TimeSeries.pdf
>>                                 >
>>                                 > but it didn’t get much attention so
>>                                 I haven’t made any effort on making
>>                                 improvements / changes to it for some
>>                                 time.
>>                                 >
>>                                 > Let me know if this goes in the
>>                                 lines of your needs!
>>                                 >
>>                                 > Cheers,
>>                                 > Ada
>>                                 >
>>                                 > ----- Mail d’origine -----
>>                                 > De: Kelle Cruz via dm <dm at ivoa.net>
>>                                 > À: dm at ivoa.net
>>                                 > Envoyé: Tue, 11 Jun 2024 22:34:39
>>                                 +0200 (CEST)
>>                                 > Objet: Lightcurve datamodel?
>>                                 >
>>                                 > Hi folks,
>>                                 >
>>                                 > I'm working on wrangling some
>>                                 lightcurves into a "standard" format. is
>>                                 > there a good reference document for
>>                                 a lightcurve datamodel? At this point,
>>                                 > I'm mostly just interested in
>>                                 header keywords.
>>                                 >
>>                                 > Thanks,
>>                                 > Kelle
>>                                 >
>>                                 > --
>>                                 > Kelle Cruz, PhD (she/her, they/them)
>>                                 > Assoc. Professor, Physics and
>>                                 Astronomy, Hunter College
>>                                 > CEO, ScienceBetter Consulting, LLC
>>                                 > CFO, Startorialist, Inc.
>>                                 <http://shop.startorialist.com>
>>                                 > Editor-in-Chief, AstroBetter Blog
>>                                 and Wiki <http://astrobetter.com>
>>                                 > Research Associate, American Museum
>>                                 of Natural History
>>                                 > Visiting Scholar, Flatiron Institute
>>                                 >
>>
>
>     -- 
>     --
>     Mireille Louys,  MCF (Associate Professor)
>     Centre de données CDS		Images, Laboratoire ICube &
>     Observatoire de Strasbourg	Telecom Physique Strasbourg
>     11 rue de l'Université		300, Bd Sebastien Brandt CS 10413
>     F- 67000-STRASBOURG		F-67412 ILLKIRCH Cedex
>     Tel: +33 3 68 85 24 34
>

-- 
--
Mireille Louys,  MCF (Associate Professor)
Centre de données CDS		Images, Laboratoire ICube &
Observatoire de Strasbourg	Telecom Physique Strasbourg
11 rue de l'Université		300, Bd Sebastien Brandt CS 10413
F- 67000-STRASBOURG		F-67412 ILLKIRCH Cedex
Tel: +33 3 68 85 24 34
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