Light curves in the IVOA

[Arnold Rots]

There is one more candidate which has the advantage of simplicity,
flexibility, and complying with the IVOA Time metadata standard:

    http://hea-www.harvard.edu/~arots/nvometa/STC/STCTimeSeriesTableFormat.pdf

There are probably a few features that are desirable in this format
(as noted), but they are easy to incorporate.

  - Arnold


Roy Williams wrote:
[ Charset ISO-8859-1 unsupported, converting... ]
> 
> To the DM and DAL groups:
> 
> With the increasing importance of synoptic surveys in modern astronomy, 
> I am thinking that the IVOA could expand its repertoire of data objects 
> to include Light Curves. An interoperable protocol for exchanging light
> curves would open the current tight connection between data and 
> classifiers, allowing different light curves to be federated, and data 
> mining codes run on data from different repositories. I propose that the 
> IVOA work towards a Simple Light Curve Access Protocol (SLiCAP).
> 
> There would be two parts to the standard, as we have with SCS, SIAP, 
> SSAP etc:
> -- How to represent a light curve as a file (Data Modeling)
> -- How to query a light curve repository (Data Access)
> 
> For the standard format, one candidate is the well-documented proposal 
> called simpleTimeSeries [1], which already has strictly defined Time, 
> and good representation of errors, bandpass, and null-detections. There 
> is also the comprehensive architectural proposal from Tody et al [2] 
> which can represent light curves and spectra in a unified way. Another 
> way to represent light curves could be derived from "Referencing STC in 
> VOTable" from Demleitner et al [3].
> 
> For the query service, we might follow what the IVOA has already done 
> with images in the SIA protocol [4]: the request is a cone (RA, Dec, 
> size) and maybe other query paramters, then the response is a table of
> possible matches, with each row having a link to the actual light curve. 
> Other elements of the query protocol might be from the Simple Time-range 
> Access Protocol [5] which essentially extends the cone-search idea to 
> include time. The only difference from SIA would be that there is a 
> light curve under the link rather than an image.
> 
> We have been discussing light-curve representation withing the VOEvent 
> WG for some time, but perhaps it would be good to open the discussion to 
> DM and DAL. I would appreciate any thoughts, comments, or relevant 
> existing work.
> 
> Roy Williams
> 
> 
> [1] http://www.dotastro.org/simpletimeseries/
> [2] http://www.ivoa.net/Documents/Notes/DAL2Arch/
> [3] http://vo.ari.uni-heidelberg.de/docs/note_stc_20100420.pdf
> [4] http://www.ivoa.net/Documents/SIA/
> [5] http://wiki.astrogrid.org/bin/view/Astrogrid/SimpleTimeAccessProtocol
> 
> -- 
> California Institute of Technology
> 626 395 3670
> 
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Arnold H. Rots                                Chandra X-ray Science Center
Smithsonian Astrophysical Observatory                tel:  +1 617 496 7701
60 Garden Street, MS 67                              fax:  +1 617 495 7356
Cambridge, MA 02138                             arots at head.cfa.harvard.edu
USA                                     http://hea-www.harvard.edu/~arots/
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