IVOA Trieste: Possible VOTable-JSON discussion?

[Marco Molinaro]

Dear all,
following this mail thread spin, the second part of the DAL session 1
(Friday Oct. 21 - 14:00 - Saturnia) has been currently reserved as a
VOTable/JSON discussion.

Even if this is set inside a DAL session, please note that Apps
participation is highly recommended, given the relevance of
formats for the Apps WG.

Cheers,
     François & Marco

2016-10-18 13:48 GMT+02:00 Marco Molinaro <molinaro at oats.inaf.it>:
> Hello Jean-Christophe,
> I forward your contribution to the lists, while waiting how to
> start/setup this splinter/meeting.
>
> Personally I think that your suggestion in probably  a step further
> than what's actually thought, but it's definitely worth keeping in
> mind.
>
> Cheers,
>      Marco
>
>
> ---------- Forwarded message ----------
> From: Malapert Jean-Christophe <Jean-Christophe.Malapert at cnes.fr>
> Date: 2016-10-18 12:48 GMT+02:00
> Subject: RE:IVOA Trieste: Possible VOTable-JSON discussion?
> To: Marco Molinaro <molinaro at oats.inaf.it>
>
>
> Hello Marco,
>
> I think it should be useful to convert to GeoJson rather than json.
> In addition, I have already a first implementation (must be improved)
> : https://github.com/malapert/JsVotable, here exactly :
> https://github.com/malapert/JsVotable/blob/master/app/converter/geojson.js
> The only one problem is to define correctly the coordinate reference system.
>
> The keyword (CRS) for the coordinate system was defined here initially :
> http://geojson.org/geojson-spec.html
>
> but this keyword was removed in the RFC7946
> (https://tools.ietf.org/html/rfc7946) because of some problems between
> OGC (Equivalent to IVOA for Earth) and the writer of the GeoJson
> format. Actually in GeoJSON format, a position is defined by
> [longitude, latitude] whereas in OGC is [latitude, longitude].
>
> If we talk about coordinate system, we need to talk about STC because
> it defines correctly a coordinate system. However, I do not think to
> have XML in GeoJSON to define a coordinate system is good. A better
> solution should be to reused WKT2 standard :
> http://docs.opengeospatial.org/is/12-063r5/12-063r5.html. The WKT is
> used here in spatialreference.org. Software uses spatialreference.org
> to get the definition of a CRS in order to make projections (ex:gdal).
> In addition, I know OGC has some discussions about WKT2 to describe
> coordinate systems for planets.
>
> Unfortunately, I will not be to IVOA to discuss about this topic.
>
> Regards,
> Jean-Christophe Malapert
>
>
> ________________________________________
> De : dal-bounces at ivoa.net [dal-bounces at ivoa.net] de la part de Marco
> Molinaro [molinaro at oats.inaf.it]
> Envoyé : mardi 18 octobre 2016 00:49
> À : François Bonnarel
> Cc : apps at ivoa.net; <dal at ivoa.net>
> Objet : Re: IVOA Trieste: Possible VOTable-JSON discussion?
>
> Hi Stelios,
> I agree with François, moreover I think that Apps should be contacted,
> even if I'm not sure about program clashes.
> Cheers
>     Marco
>
> Il 17 ott 2016 23:15, "BONNAREL Francois (OBS)"
> <francois.bonnarel at astro.unistra.fr<mailto:francois.bonnarel at astro.unistra.fr>>
> ha scritto:
>>
>>
>> Dear Stelios,
>>
>>     This is exactly the kind of things we had in mind with the "DAL"  future discussion. Not sur it will be in DAL1 or DAL3 yet. We can add a lunch together if necessary, but i think it worth wheile to be discussed in full session.
>>
>>
>> Regards to all
>>
>> François
>>
>> Le Lundi 17 Octobre 2016 22:12 CEST, Stelios Voutsinas <stv at roe.ac.uk<mailto:stv at roe.ac.uk>> a écrit:
>>
>> > Hello DAL,
>> >
>> > Following from some offline discussions we had during the IVOA Interop in South Africa, as well as discussions on the mailing list regarding a JSON VOTable output, I've compiled some notes into a wiki page which can be found here: http://wiki.ivoa.net/twiki/bin/view/IVOA/VOTable-JSONdiscussion
>> >
>> > Would there be interest in organizing an unofficial discussion for anyone interested in this during the Interop in Trieste? If there is enough interest, perhaps we could schedule something after the main sessions.
>> >
>> > Cheers,
>> >
>> > Stelios Voutsinas
>> > WFAU, University of Edinburgh
>>
>>
>>