Time Domain presentation at CSP

[Matthew Graham]

Hi Enrique,

A practical use case that I am facing at the moment is to represent a time series consisting of data from three different surveys (so the error models are different and heteroskedastic) with upper limit detections in some cases, e.g., there was no detection on MJD = 56123.12343 but the 95% detection limit of the image frame is V = 20.54.

	Cheers,

	Matthew



On Jun 18, 2015, at 12:33 AM, esm wrote:

> Hi Rob,
> 
>> The IVOA has never met a “type” paradigm it never liked.  Is DatasetType supposed to provide an exhaustively exclusive list of all possible variations of time series, etc?  Or is it rather more like a mime type in concept; capturing the broad essence like “I am an image” versus “I am a spectrum” versus “I am a time series”?
> I guess it is more a broad definition of the type of product.
> 
>> More to the point there will never be crowds clamoring for data models.  Rather, they will clamor for practical file formats and the tools and libraries needed to create them for internal use and for interchange. The amount of clamor will be directly proportional to actual science they want to achieve, not to any philosophical vision of computing.
> 
> I agree. People started to do VO-science once tools like Aladin, TOPCAT or VOSA were available; tools that, taking advantage of the standardization behind the scene,  allow users to discover, gather and analyse data in an efficient way. That is the level we should reach for time series. But we don't even have standards yet...
> 
>> STS was never just an interim IVOA DM “solution”,
> It was. Have a look at the IVOA Note "Employing SimpleTimeSeries for representing time series" (Graham et al.)
> http://www.ivoa.net/documents/Notes/SimpleTimeSeries/index.html
> 
>> Perhaps the question might best be posed as how to represent SDM v2.0 compliant data using STS. Maybe this will require adding some parameters to STS, but this will be more persuasive after attending to Arnold’s comments, for instance. In general IVOA will find more success at incrementally evolving pre-existing standards (toward adherence to shiny new IVOA DMs) than with convincing astronomers and projects to drop what they are doing and pick up something new entirely.
> 
> Yes but I am a data provider willing to publish light curves in the VO. Almost three years ago, in the Sao Paulo interop, I raised the need for a data model for light curves. At that time, STS seemed the best option as only some minor modifications were needed to properly describe simple time series (my case, magnitude vs time). Nevertheless nothing happened and now SDM seems more adequate for my service. That's why, if I have to choose now, I would choose SDM.
> 
> Cheers,
> 
> Enrique.
> 
> -- 
> Enrique Solano Márquez
> Spanish Virtual Observatory
> Centro de Astrobiología (INTA-CSIC)
> Campus Villafranca.
> P.O. Box 78
> 28691 Villanueva de la Cañada
> Madrid, Spain
>