[mapserver-users] WCS with elevation data

[Berger, Cora]

Hello list,
I created a WCS with MapServer 7 (on windows), which displays elevation data. 
I have some problems which I can't solve and hope you can support me.

1.) Since I'm using a Tileindex I need to fill the Layers metadata-tags "wcs_size" and wcs_resolution". Unfortunately, the documentation of MapServer doesn't give a hint what values to use for this tags. I read somewhere that the values come from GDAL when you create the Tileindex with GDAL, but I didn't create the index with GDAL.

2.) The Input data are 1km tiles with 2000 x 2000 x 8 BPP, 32-bit, 96dpi. If I request the WCS I get a 24-bit image back. I tried to define different output formats, but couldn't find a solution yet.

3.) I tried to display the WCS in QGIS, which works, but it works really slow and I get an image with huge pixels back. If I request the height values and compare it to the original data, they are correct, but instead of float-values I get integer-values back. E. g. 42,33355m becomes 42m. Is there a way to influence this?

4.) If I request the WCS via browser with version=1.0.0 I get a fast response. If I request it with version 2.0 I always get a Timeout. Is there a problem with the different versions? Maybe that explains why QGIS is so slow.

You find my mapfile below:

MAP 
  EXTENT 278000 5560000 536000 5828000
  IMAGECOLOR 255 255 255
  NAME "WCS_NW_DGM"
  FONTSET    "C:/ms4w/apps/GDI/fonts/fonts.list" # True-Type Schriften
  MAXSIZE 5000
  RESOLUTION 90.714285714285714285714285714286
  STATUS on
  UNITS meters


  PROJECTION
    "init=epsg:25832"
  END

  WEB
    imagepath "/tmp/"
    imageurl "/tmp/"
    
    METADATA
      "wcs_enable_request"   "*"
      "wcs_label" "WCS DGM"
      "wcs_encoding" "UTF-8"
      "wcs_title"            "WCS NW DGM"
      "wcs_onlineresource"   "http://vbrk21nt15.bezreg-koeln.nrw.de/wms/wcs_nw_dgm"
	  "wcs_description"		"Höhenberechnungsdienst auf Basis des DGM"
	  "wcs_keywordlist" 	"NRW-Atlas,NW,NRW,Bezirksregierung Köln,Abteilung 7,Geobasis NRW,Geobasisdaten,Landesvermessung,AdV,Arbeitsgemeinschaft der Vermessungsverwaltungen der Länder"      
    
	END
  END

#-----LAYER-----

LAYER
  NAME "nw_dgm"
  TILEINDEX "//bezreg-koeln.nrw.de/BRK/Abt7/72_URA/NAS/URA/DGM1/utm32/DGM1"
  TILEITEM "LOCATION"	  
  STATUS ON
  TYPE RASTER
  MINSCALE 1
  MAXSCALE 50001

  PROJECTION
    "init=epsg:25832"
  END

  METADATA
	"ows_srs" "EPSG:25832"
    "wcs_extent"  	"278000 5560000 536000 5828000"
    "wcs_size" "600 600"
    "wcs_resolution" "1 1"
    "wcs_label" "DGM Hoehen"
    "wcs_native_format" "32-bit GeoTIF"
    "wcs_rangeset_name" "Range 1"
    "wcs_rangeset_label" "DGM Höhen"
    END
END 
END #map

Thanks in advance for any help!

                
Cora