[mapserver-users] RE: WCS GetCoverage

[David Hildebrand]

Jukka:

I am running MapServer 5.2.1 and am being explicit about W** version.
For WMS I am using version 1.1.1 and WCS version 1.0.0 but that is
hidden in a CGI wrapper.  I did find out, however, that in my WCS
request I need to specify the RESX and RESY units the same as the CRS
projection units (in this case degrees) and I also need to specify the
RESPONSE_CRS the same as the CRS.  These are odd behaviours.  One should
be able to request the response in a different projection than the
bounding box and specify the resolution in the units of the output
projection.  The projections I am using are all specified in the
"ows_srs" line of the mapserv.map file. 



===========================
David V. Hildebrand
Agriculture Financial Services Corporation
(403) 782-8239   
-----Original Message-----
From: Rahkonen Jukka [mailto:Jukka.Rahkonen at mmmtike.fi] 
Sent: Thursday, November 24, 2011 2:06 PM
To: David Hildebrand; mapserver-users at lists.osgeo.org
Subject: Re: WCS GetCoverage

Hi,

Very first thing to do with all the W** services is to give always an
explicit VERSION=
Request can sometimes work even without but then the default is the
highest supported.  Do not play with defaults, take the control for
yourself.
What Mapserver version you have? Perhaps some old 5.x which supports
only WCS 1.0 because otherwise I suppose you would get some other error
message with your request.

-Jukka Rahkonen-

________________________________
David Hildebrand wrote:

I am trying to implement a WCS server and am running into difficulty
with GetCoverage and the following request.

REQUEST=GetCoverage&COVERAGE=awifs&CRS=EPSG:4269&BBOX=-116,51,-114,53&RE
SX=100&RESY=100&FORMAT=GTiff&RESPONSE_CRS=EPSG:4269

The following ServiceException is raised.

msImageCreateGD(): Image handling error. Cannot create GD image of size
0x0

I can do a WCS GetCapabilities and DescribeCoverage without error.
Also, when I issue the following WMS request it works fine.

REQUEST=GetMap&LAYERS=awifs&SRS=EPSG:4269&BBOX=-116,51,-114,53&WIDTH=800
&HEIGHT=600&FORMAT=image/png&STYLES=

The GetCoverage and GetMap requests have the same parameters and yet WCS
thinks the image size is 0x0.  The MapServer configuration for the layer
file is given below

LAYER
  NAME "awifs"
  PROCESSING "BANDS=2,1,3"
  PROCESSING "SCALE_2=19,159"
  PROCESSING "SCALE_1=10,130"
  PROCESSING "SCALE_3=9,124"
  METADATA
    "wcs_label" "awifs"
    "wcs_rangeset_name" "RGB"
    "wcs_rangeset_label" "rgb"
    "wms_title" "awifs"
    "wms_opaque" "1"
    "ows_resolution" "56 56"
    "wms_srs" "EPSG:43001"
  END
  STATUS off
  TYPE raster
  DATA "e:/awifs/July.tif"
  PROJECTION
    "init=epsg:43001"
  END
  TEMPLATE "empty.html"
  DUMP TRUE
END

Thanks for the help.


===========================
David V. Hildebrand
Agriculture Financial Services Corporation
(403) 782-8239
________________________________