[mapserver-users] WMS - getCapabilities BBOX

[Guillaume Sueur]

Ok for the ticket. I'm going to read carefully your comments not to 
write non-sense !

Doing some further investigations, I noted that the WFS getCapabilities 
sends back a LatLongBoundingBox (don't forget the G to long for WFS... 
don't know why this parameter hasn't got the exact same name in WFS and 
WMS...) in WGS84 where the WFS specs say "The LatLongBoundingBox element 
is used to indicate the edges of an enclosing rectangle in the SRS of 
the associated feature type."

I may be wrong on this interpretation, but fixing the GetCapabilities 
XML doc on the fly allowed me to display my data.

Best regards,

Guillaume


Frank Warmerdam a écrit :
> Guillaume Sueur wrote:
>> Hi,
>>
>> I've got a problem with mapserver's WMS getCapabilities. My data are 
>> projected in a local projection (EPSG:27563). Apparemtly, the 
>> getCapabilities calculates a LatLongBoundigBox, given in WGS84. But 
>> these values are wrong, with a serious shift on the west.
>> When I translate the data with ogr2ogr to EPSG:4326 in KML, tha data 
>> is at the correct place in GoogleEarth.
> 
> Guillaume,
> 
> EPSG:27563 has a prime meridian other than greenwich. I presume that is
> causing the problem.  In fact, looking through the code I think the latlong
> box is actually computed in the GCS of the coordinate system in question,
> rather than WGS84.  So in your case there is a serious error in the east
> west axis, but in other situations people may see small errors due to the
> lack of datum adjustment.
> 
> I would suggest you file a ticket on it.  Specifically the ticket might
> note that msOWSPrintLatLonBoundingBox() just passes NULL for the 
> destination
> coordinate system, and msProjectPoint() just treats this as a special case
> to use the lat/long coordinate system (GCS) associated with the projected
> coordinate system.  So in this case we see a big error because you are 
> getting
> values relative to the paris prime meridian.
> 
> This is likely to affect a number of places in MapServer (WMS, and WCS
> at least).  Please add me ("warmerdam") as a cc on the created ticket.
> I might not fix it, but I should at least be able to help.
> 
> Best regards,