Minutes of Telecon 25 January 2011

Attendees

• John Schattel (NWS),
• Adrian Custer (Geomatys),
• Michael Weiss (IBL)
• Frederic Guillaud (Meteo-France)
• Marie-Francoise Voidrot (Meteo-France)

Proposed Agenda

1. Return of experience on current IEs
2. Update on the works going on via the email list and the twiki on CRSs
3. Next Telcon

1) Return of experience on current IEs :

Meteo-France is testing all servers available on MetocWMS_Servers page and feeding progressively [[http://external.opengis.org/twiki_public/bin/view/MetOceanDWG/MetocWMS_WMS_IE_Retex][ Return of Experience of WMS Interoperability Experiments]

Main problems detected :

• Some URL have the date of the run into the URL : it is difficult to handle a changing URL for the clients
• The default style isn't declared into the getcapabilities. The Profile could define a pool basic styles for simple basic parameters in order to be sure that all server serve a common style for the same field => inform Illka and Chris who manage the Style and SLD/SE issues
• most of the images are 24 bits which requires 32 bits to handle transparency
• need to get the correspondance between numerical values and physical values
• All servers serve different data so it limitates the possibilities to test a unique Use case at this stage

We should encourage the server providers to serve a basic set of fields (MSLP, temperature) for the I.E.

2) CRSs :

The twiki page : http://external.opengis.org/twiki_public/bin/view/MetOceanDWG/MetCoordinateReferenceSystemDefinition

has been updated

Everybody is warmly encouraged to complete the paragraph "Other needed CRS definitions:" if needed.

During the teleconf , we reviewed the CRS needed and already identified as needed and missing into WMS1.3 possibilities by now

• orthographic : Eumetsat who had asked for it confirm they don't really need it.
• Geos : This projection is defined into the document GCMS 03 "HRIT-LRIT Global Specification". It seems there is a problem of datum on this projection. There is a proj4 definition at : http://spatialreference.org/ref/sr-org/81/ and http://spatialreference.org/ref/sr-org/81/proj4js/, but with an error as it is defined with a WGS4 datum. Maybe this error is volunteer due to the fact that the real datum is specific and the approximation is maybe acceptable. Meteo-France estimates the error around 200 meters. Initiating contacts on the issue with WMO It will be added into the WMS2.0 spec.
• parametric CRS : Adrian also confirmed there is space into WMS2.0 to define parametric CRS and be able to define a central meridian.
• PROJ4 definitions : Marie-francoise has sent an email to Illka. No answer at the moment

Chris took an action to check if there are specific CRSs missing to fulfill aeronautics requirements. He sent an email on the 14th of December around this action. This email content will be integrated or synthetesized into the twiki page.

EPSG : 4326 seems to be a common CRS everybody can handle. It could be a recommendation into the Met Ocean WMS Profile to handle this CRS on all Met Ocean Servers. We could define a minimum set of CRss to be served by the Met Ocean servers and handled by the Met Ocean clients.

Please complete it before the 31rd of January of possible to feed in the discussions of the next teleconf.

Thank you all for your contributions.

4) Next Telcon

31rd of January 2011 16:00 UTC

-- MarieFrancoiseVoidrotMartinez - 28 Jan 2011