- From: Raphaël Troncy <raphael.troncy@eurecom.fr>
- Date: Mon, 5 Sep 2016 15:41:47 +0200
- To: Frans Knibbe <frans.knibbe@geodan.nl>, Rob Atkinson <rob@metalinkage.com.au>
- Cc: Bruce Bannerman <B.Bannerman@bom.gov.au>, SDW WG Public List <public-sdw-wg@w3.org>
Dear Frans, > But if there are cases where publishing data with multiple CRSs is > a hard rule that must be complied with it would be good to have them in > the UCR document. And that would probably mean we have to formulate > another requirement in the UCR doc, e.g. 'it must be possible to publish > geometric data with multiple CRSs'. I have a good example, that I used already many years ago during my presentation at the workshop that precedes the creation of this joint OGC-W3C working group. Have a look at this dataset published on the French Government Open Data Portal: https://www.data.gouv.fr/fr/datasets/adresse-et-geolocalisation-des-etablissements-denseignement-du-premier-et-second-degres/. This dataset is provided in the CSV format. It lists all primary and secondary schools in France, with their geo-coordinates, name, address, state, etc. While there is a single file, the various values of the columns 'coordonnee_x' and 'coordonnee_y' MUST be interpreted differently. The explanatory note adds the following information: "The coordinates X and Y are provided by IGN according to various CRS / projections being used:" - France métropolitaine: RGF93 - Lambert 93 - Guadeloupe: WGS84 - UTM Nord fuseau 20 - Martinique : WGS84 - UTM Nord fuseau 20 - Guyane : RGFG95 - UTM Nord fuseau 22 - Réunion : RGR92 - UTM Sud fuseau 40 This means that depending on which places you are on earth, you have to interpret geo-coordinates differently, otherwise, you will plot schools in the middle of the sea ... Best regards. Raphaël -- Raphaël Troncy EURECOM, Campus SophiaTech Data Science Department 450 route des Chappes, 06410 Biot, France. e-mail: raphael.troncy@eurecom.fr & raphael.troncy@gmail.com Tel: +33 (0)4 - 9300 8242 Fax: +33 (0)4 - 9000 8200 Web: http://www.eurecom.fr/~troncy/
Received on Monday, 5 September 2016 13:42:44 UTC