Lightcurve datamodel?

CresitelloDittmar, Mark mdittmar at cfa.harvard.edu
Thu Jun 13 20:47:08 CEST 2024


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
>>>>> >
>>>>>
>>>>
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