Re: W3C/OGC WG Launched!

On 2015-01-13 5:42, Simon.Cox@csiro.au wrote:
> Another possible consideration:
>
> JSON-LD is being talked about as a viable serialization format for RDF data - some folk are suggesting that it will soon be the default, thus also helping with RDF's developer-acceptability problem. In which case, the issue of overlaps between LOCN, GeoJSON, and other RDF vocabularies becomes more urgent and maybe more tractable.
>
> I am aware that the GeoJSON team has some thoughts around moving CRS support into a "-LD" extension to GeoJSON [1]. Now while the GeoJSON team are mostly concerned with the encoding, lets please make sure that the implications of this option to the RDF view is considered. I'm not yet familiar enough with JSON or JSON-LD to tease it out, so I hope someone else maybe has the knowledge and motivation.
>
> [1] https://github.com/geojson/geojson-ld/issues/27
Thanks for the notification.
Until now I haven't had any experience with GeoJSON, but I have played 
with JSON-LD. As far as I know, JSON-LD is a notation for RDF graphs, so 
it is similar to other RDF formats like Turtle and RDF/XML. So whatever 
definition of CRS we come up with, it should be fine in JSON-LD.

GeoJSON on the other hand seems to be an alternative notation for 
geographical data. So it is similar to WKT or GML. Personally, I think 
geospatial data are better off making use of common models like RDF 
instead of using yet another domain specific model, but again I see no 
conflict. Perhaps it would be beneficial for GeoJSON-LD if they can use 
locn:crs instead of having to define geojson:crs?

Reading some of the discussion going on at GeoJSON, it seems that a big 
gripe is with the old style CRS definitions, as standardised by the 
EPSG. The main problem there is that geodetical reference systems (those 
using degrees instead of meters as units) usually have a different axis 
order, meaning that coordinates take the form of (latitude,longitude), 
which translates to (y,x) in the cartesian systems that are used for 
flat maps. This causes headaches among web developers. But I think the 
OGC already solved that problem (or is solving that problem?) by 
removing references to EPSG from CRS definitions. For example, 
http://www.opengis.net/def/crs/OGC/1.3/CRS84 is just like EPSG:4326, 
only the axis order is different. If everyone starts using those new OGC 
definitions, there no longer will be axis order confusion.

Regards,
Frans


>
> -----Original Message-----
> From: Andrea Perego [mailto:andrea.perego@jrc.ec.europa.eu]
> Sent: Saturday, 10 January 2015 12:44 AM
> To: Frans Knibbe | Geodan
> Cc: LocAdd W3C CG Public Mailing list
> Subject: Re: W3C/OGC WG Launched!
>
> Very good news indeed!
>
> I do agree with Frans that it would be important to consolidate the LOCN voc, so that it can be used as an input to the SDW WG.
>
> I'm going to open a separate thread on this.
>
> Cheers,
>
> Andrea
>
>
> On Fri, Jan 9, 2015 at 12:42 PM, Frans Knibbe | Geodan <frans.knibbe@geodan.nl> wrote:
>> Hello Phil,
>>
>> Excellent news! A lot has been going on in getting spatial data to
>> work on the web, but that work is quite fragmented. I hope the new
>> workgroup will serve as a focal point for many interrelated efforts.
>> Thank you for your contributions in making this happen! I guess it wasn't the easiest of tasks.
>>
>> And I am sure the LOCN vocabulary can play an important role,
>> providing low-threshold semantics for location data. All the more
>> reason to take the job of maintaining the vocabulary seriously.
>>
>> Some of the things that come to mind as things we can give some extra
>> attention to this year:
>>
>> Finish the task of providing explanatory text in multiple languages;
>> Finish the proposal for adding CRS and spatial resolution to the
>> vocabulary; Solicit experiences from people in the field who are using
>> the vocabulary and see if this gives reasons for change or consolidation.
>>
>> Regards,
>> Frans
>>
>> On 2015-01-06 17:28, Phil Archer wrote:
>>
>> Dear all,
>>
>> As you may have seen an hour or so ago, the much talked about
>> collaboration between W3C and OGC is under way!
>>
>> The two standards bodies issued a joint press release today and, if
>> you're eligible, obviously we'd be delighted if you were to join the working group.
>>
>> Relevant Links:
>>
>> The press release
>> http://www.w3.org/blog/news/archives/4287
>>
>> The Working Group
>> https://www.w3.org/2015/spatial/
>>
>> OGC have analogous pages too of course.
>>
>> Something of particular relevance to the LOCADD CG is that the charter
>> for this new WG is sufficiently flexible that it could potentially
>> provide a vehicle for more formal standardisation of the LOCN vocab.
>>
>> Cheers
>>
>> Phil.
>>
>>
>>
>> ________________________________
>> Frans Knibbe
>> Geodan
>> President Kennedylaan 1
>> 1079 MB Amsterdam (NL)
>>
>> T +31 (0)20 - 5711 347
>> E frans.knibbe@geodan.nl
>> www.geodan.nl | disclaimer
>> ________________________________
>
>
> --
> Andrea Perego, Ph.D.
> European Commission DG JRC
> Institute for Environment & Sustainability Unit H06 - Digital Earth & Reference Data Via E. Fermi, 2749 - TP 262
> 21027 Ispra VA, Italy
>
> https://ec.europa.eu/jrc/
>
> ----
> The views expressed are purely those of the writer and may not in any circumstances be regarded as stating an official position of the European Commission.
>


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Frans Knibbe
Geodan
President Kennedylaan 1
1079 MB Amsterdam (NL)

T +31 (0)20 - 5711 347
E frans.knibbe@geodan.nl
www.geodan.nl <http://www.geodan.nl> | disclaimer 
<http://www.geodan.nl/disclaimer>
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