[mapserver-users] Problems serving GeoTifs as .bil

[Evans, James R Civ USAF ACC 84 RADES/SCZE]

Hi, 
I'm having bad results trying serve elevation data from GMTED2010 geotifs as .bil.  On the client side, the file I get is the right size, however only the low byte of the 16 bit word has any values.  The high 8 bits are always zero.  That has the effect of making all of my elevations appear to be between 0 and 255 meters.  If I try to download the data as 32 bit tifs, it works fine.  Unfortunately, my client app is looking for .bils.  Here's the start of my map file.  I'm using the MS4W latest released version.  Any help would be appreciated! 
Thanks, 
James 

Here's what one of my requests looks like: 
http://localhost/cgi-bin/gmted.exe?service=WMS&request=GetMap&version=1.1.1&srs=EPSG:4326&layers=GMTED&styles=&format=image/bil&width=150&height=150&bbox=-120.0,30.0,-100.0,50.0&



Start of my Map file: 

MAP 
  NAME "GMTED" 
  EXTENT -180 -90 180 90 
  SIZE 512 512 
  UNITS DD 
  IMAGETYPE image/bil 

  PROJECTION 
    "init=epsg:4326" 
  END 

  OUTPUTFORMAT 
    NAME "asc" 
    DRIVER "GDAL/AAIGrid" 
    MIMETYPE "application/asc" 
    EXTENSION "asc" 
    IMAGEMODE INT16 
  END 

  OUTPUTFORMAT 
    NAME "bil" 
    DRIVER "GDAL/EHdr" 
    MIMETYPE "image/bil" 
    EXTENSION "bil" 
    IMAGEMODE INT16 
  END 

  OUTPUTFORMAT 
    NAME "bil16" 
    DRIVER "GDAL/EHdr" 
    MIMETYPE "application/bil16" 
    EXTENSION "bil" 
    IMAGEMODE INT16 
  END 

  OUTPUTFORMAT 
    NAME "tif" 
    DRIVER "GDAL/GTiff" 
    MIMETYPE "image/tiff" 
    EXTENSION "tif" 
    IMAGEMODE FLOAT32 
  END 

  WEB 
    METADATA 
      wms_title "GMTED Terrain" 
      wms_srs "EPSG:4326 EPSG:900913" 
      ows_onlineresource "http://localhost/cgi-bin/GMTED" 
      ows_enable_request "*" 
    END 
  END