[mapserver-users] RE: Reprojecting cascading WMS requests (Rob)

[Mark Volz]

Rob,

Anyone can correct me if I am wrong on this however I think you have to enter
projection information in 3 times.

1) the projection of your map
2) the projection of your data, in this case the wms service so that
mapserver knows what to reproject from.
3) the projection that you are requesting from the wms service - in the
metadata section.

I am doing this on some of my applications so let me know if your having
trouble, otherwise if someone has a better thought let me know if I am
wasting lines of code.

Example:

MAP
...
Projection # of the Map
End Projection
...
..
	Layer
	Projection # of the Source
	End Projection
	...
	Metadata
		"wms_srs" "ESPG:27700"  #projection you are requesting in WMS
	....
	End #Metadata
	...
End #layer

Mark Volz
GIS Specialist
Lyon County, MN
(507) 532-8218

----------------------------------------------------------------------

Message: 1
Date: Fri, 10 Jul 2009 17:23:28 +0100
From: Rob <gis at vanbooth.com>
Subject: [mapserver-users] Reprojecting cascading WMS requests
To: mapserver-users at lists.osgeo.org
Message-ID:
	<2a955f950907100923m1ad368b7m8eb9e00727d29baa at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

Hi

I'm obviously having Friday afternoon blindness, as I can't see what I
am doing wrong!  I am trying to set up a basic Mapserver install (MS4W
v3.0 Beta 4)

MapServer version 5.4.1 OUTPUT=GIF OUTPUT=PNG OUTPUT=JPEG OUTPUT=WBMP
OUTPUT=PDF
 OUTPUT=SWF OUTPUT=SVG SUPPORTS=PROJ SUPPORTS=AGG SUPPORTS=FREETYPE
SUPPORTS=ICO
NV SUPPORTS=FRIBIDI SUPPORTS=WMS_SERVER SUPPORTS=WMS_CLIENT
SUPPORTS=WFS_SERVER
SUPPORTS=WFS_CLIENT SUPPORTS=WCS_SERVER SUPPORTS=SOS_SERVER SUPPORTS=FASTCGI
SUP
PORTS=THREADS SUPPORTS=GEOS SUPPORTS=RGBA_PNG INPUT=JPEG INPUT=POSTGIS
INPUT=OGR
 INPUT=GDAL INPUT=SHAPEFILE


which points to a WMS service which only supports a single projection.
I want to get my Mapserver to reproject that data on the fly to other
projection systems, but don't seem to be doing it right!

This is my mapfile

MAP
NAME SPIRIT
STATUS ON
SIZE 600 600
EXTENT 0 0 650000 1300000
UNITS METERS
SHAPEPATH "temp"
IMAGECOLOR 255 255 255
#FONTSET 'fontset.txt'

#SYMBOLSET 'temp/examples.sym'

IMAGETYPE JPEG
IMAGEQUALITY 75

IMAGETYPE png
OUTPUTFORMAT
   NAME png
   DRIVER "GD/PNG"
   MIMETYPE "image/png"
   IMAGEMODE rgb
END

IMAGETYPE jpeg
OUTPUTFORMAT
   NAME jpeg
   DRIVER "GD/JPEG"
   MIMETYPE "image/jpeg"
   IMAGEMODE rgb
END

PROJECTION
 "init=epsg:27700"
END

WEB
  IMAGEPATH "c:\temp\"
  METADATA
    WMS_TITLE "WMS Server"
    WMS_ABSTRACT "WMS Server."
	WMS_ONLINERESOURCE
"http://localhost/cgi-bin/mapserv.exe?map=example.map&"
    WMS_SRS "EPSG:27700 ESPG:4326"
  END
END

  LAYER
	NAME "layer"
	TYPE RASTER
	STATUS ON
	CONNECTION "http://externalwmshost/&"
	CONNECTIONTYPE WMS
	METADATA
		"wms_srs"			"EPSG:27700"
		"wms_name"			"layername"
		"wms_server_version"	"1.1.1"
		"wms_formatlist"	"image/png,image/jpeg"
	 END
   END

END

END # Map File


but when I make a WMS request against it

http://localhost/cgi-bin/mapserv.exe?map=example.map&request=getmap&service=w
ms&layers=layer&bbox=53.5,1.4,53.51,1.41&width=400&height=400&version=1.1.1&s
rs=EPSG:4326&format=jpeg

I get


<?xml version='1.0' encoding="ISO-8859-1" standalone="no" ?>
<!DOCTYPE ServiceExceptionReport SYSTEM
"http://schemas.opengis.net/wms/1.1.1/exception_1_1_1.dtd">
<ServiceExceptionReport version="1.1.1">
<ServiceException code="InvalidSRS">
msWMSLoadGetMapParams(): WMS server error. Invalid SRS given : SRS
must be valid for all requested layers.
</ServiceException>
</ServiceExceptionReport>

I'm guessing I'm missing something simple, but I don't know what it
is.  Any help gratefully accepted!

Thanks

Rob