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<TITLE>Problem using gdal_translate on netcdf file</TITLE>
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<P><FONT SIZE=2 FACE="Arial">Hi All,</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">I'm trying to convert a netcdf file to some an image format that I can use with imagemagick (tiff, jpg, png, anything will do). Unfortunately, I'm having some troubles getting the job done. When I try gdal_translate with any format other than Gtiff I get a completely black image. When I use the Gtiff format, I get a weird grayscale mutated version of my source file, with strange grainy vertical bands. When I open the netcdf file in OpenEV it looks perfectly normal, and I use the netcdf file for a lot of different data processing, so I feel confident that the data itself is good (if not the formatting of the data).</FONT></P>
<P><FONT SIZE=2 FACE="Arial">I've placed a subsetted version of the translated image online to show what the resulting geotiff looks like, it's here:</FONT></P>
<P><A HREF="http://www.mbari.org/staff/achase/vdm/hrbath.tif"><U><FONT COLOR="#0000FF" SIZE=2 FACE="Arial">http://www.mbari.org/staff/achase/vdm/hrbath.tif</FONT></U></A>
<BR><FONT SIZE=2 FACE="Arial">Maybe someone else has seen this same type of image problem?</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">Here's the gdalinfo output:</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">C:\workspace\vdm\resources\grids>gdalinfo NETCDF:"hrbath.nc":elevation</FONT>
<BR><FONT SIZE=2 FACE="Arial">Driver: netCDF/Network Common Data Format</FONT>
<BR><FONT SIZE=2 FACE="Arial">Size is 5001, 4001</FONT>
<BR><FONT SIZE=2 FACE="Arial">Coordinate System is `'</FONT>
<BR><FONT SIZE=2 FACE="Arial">Origin = (-125.000000000000000,38.000999999999998)</FONT>
<BR><FONT SIZE=2 FACE="Arial">Pixel Size = (0.000999800039992,-0.000999750062484)</FONT>
<BR><FONT SIZE=2 FACE="Arial">Metadata:</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NC_GLOBAL#creationDate=01/19/2007</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NC_GLOBAL#lastModified=01/19/2007</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NC_GLOBAL#Conventions=CF-1.0</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NC_GLOBAL#CreatedBy=VARS Data Mining Software - MBARI</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NC_GLOBAL#title=DEM Grid from hrbath.asc</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NC_GLOBAL#institution=MBARI</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NC_GLOBAL#creator_name=Andrew Chase</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NC_GLOBAL#keywords=dem bathymetry grid</FONT>
<BR><FONT SIZE=2 FACE="Arial"> elevation#positive=up</FONT>
<BR><FONT SIZE=2 FACE="Arial"> elevation#long_name=Elevation</FONT>
<BR><FONT SIZE=2 FACE="Arial"> elevation#missing_value=-9.999900e+004</FONT>
<BR><FONT SIZE=2 FACE="Arial"> elevation#units=meters</FONT>
<BR><FONT SIZE=2 FACE="Arial"> latitude#units=degrees_north (+N/-S)</FONT>
<BR><FONT SIZE=2 FACE="Arial"> longitude#units=degrees_east (+E/-W)</FONT>
<BR><FONT SIZE=2 FACE="Arial">Corner Coordinates:</FONT>
<BR><FONT SIZE=2 FACE="Arial">Upper Left (-125.0000000, 38.0010000)</FONT>
<BR><FONT SIZE=2 FACE="Arial">Lower Left (-125.0000000, 34.0010000)</FONT>
<BR><FONT SIZE=2 FACE="Arial">Upper Right (-120.0000000, 38.0010000)</FONT>
<BR><FONT SIZE=2 FACE="Arial">Lower Right (-120.0000000, 34.0010000)</FONT>
<BR><FONT SIZE=2 FACE="Arial">Center (-122.5000000, 36.0010000)</FONT>
<BR><FONT SIZE=2 FACE="Arial">Band 1 Block=5001x1 Type=Float32, ColorInterp=Undefined</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NoData Value=-99999</FONT>
<BR><FONT SIZE=2 FACE="Arial"> Metadata:</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NETCDF_VARNAME=elevation</FONT>
<BR><FONT SIZE=2 FACE="Arial">----------------------------------------------------------------------------------------------------------</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">And here's the translation I'm trying:</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">C:\workspace\vdm\resources\grids>gdal_translate -of GTiff -a_nodata -99999 NETCD</FONT>
<BR><FONT SIZE=2 FACE="Arial">F:"hrbath.nc":elevation hrbath.tif</FONT>
<BR><FONT SIZE=2 FACE="Arial">Input file size is 5001, 4001</FONT>
<BR><FONT SIZE=2 FACE="Arial">0...10...20...30...40...50...60...70...80...90...100 - done.</FONT>
<BR><FONT SIZE=2 FACE="Arial">----------------------------------------------------------------------------------------------------------</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">And the resulting gdalinfo output:</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">C:\workspace\vdm\resources\grids>gdalinfo hrbath.tif</FONT>
<BR><FONT SIZE=2 FACE="Arial">Driver: GTiff/GeoTIFF</FONT>
<BR><FONT SIZE=2 FACE="Arial">Size is 5001, 4001</FONT>
<BR><FONT SIZE=2 FACE="Arial">Coordinate System is `'</FONT>
<BR><FONT SIZE=2 FACE="Arial">Origin = (-125.000000000000000,38.000999999999998)</FONT>
<BR><FONT SIZE=2 FACE="Arial">Pixel Size = (0.000999800039992,-0.000999750062484)</FONT>
<BR><FONT SIZE=2 FACE="Arial">Metadata:</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NC_GLOBAL#creationDate=01/19/2007</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NC_GLOBAL#lastModified=01/19/2007</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NC_GLOBAL#Conventions=CF-1.0</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NC_GLOBAL#CreatedBy=VARS Data Mining Software - MBARI</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NC_GLOBAL#title=DEM Grid from hrbath.asc</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NC_GLOBAL#institution=MBARI</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NC_GLOBAL#creator_name=Andrew Chase</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NC_GLOBAL#keywords=dem bathymetry grid</FONT>
<BR><FONT SIZE=2 FACE="Arial"> elevation#positive=up</FONT>
<BR><FONT SIZE=2 FACE="Arial"> elevation#long_name=Elevation</FONT>
<BR><FONT SIZE=2 FACE="Arial"> elevation#missing_value=-9.999900e+004</FONT>
<BR><FONT SIZE=2 FACE="Arial"> elevation#units=meters</FONT>
<BR><FONT SIZE=2 FACE="Arial"> latitude#units=degrees_north (+N/-S)</FONT>
<BR><FONT SIZE=2 FACE="Arial"> longitude#units=degrees_east (+E/-W)</FONT>
<BR><FONT SIZE=2 FACE="Arial">Corner Coordinates:</FONT>
<BR><FONT SIZE=2 FACE="Arial">Upper Left (-125.0000000, 38.0010000)</FONT>
<BR><FONT SIZE=2 FACE="Arial">Lower Left (-125.0000000, 34.0010000)</FONT>
<BR><FONT SIZE=2 FACE="Arial">Upper Right (-120.0000000, 38.0010000)</FONT>
<BR><FONT SIZE=2 FACE="Arial">Lower Right (-120.0000000, 34.0010000)</FONT>
<BR><FONT SIZE=2 FACE="Arial">Center (-122.5000000, 36.0010000)</FONT>
<BR><FONT SIZE=2 FACE="Arial">Band 1 Block=5001x1 Type=Float32, ColorInterp=Gray</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NoData Value=-99999</FONT>
<BR><FONT SIZE=2 FACE="Arial"> Metadata:</FONT>
<BR><FONT SIZE=2 FACE="Arial"> NETCDF_VARNAME=elevation</FONT>
</P>
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<P><FONT SIZE=2 FACE="Courier New">Any ideas of what to try would be appreciated.</FONT>
</P>
<P><FONT SIZE=2 FACE="Courier New">-Andrew</FONT>
</P>
<BR>
<P><FONT SIZE=2 FACE="Courier New">Andrew C. Chase</FONT>
<BR><FONT SIZE=2 FACE="Courier New">Software Engineer</FONT>
<BR><FONT SIZE=2 FACE="Courier New">Monterey Bay Aquarium Research Institute</FONT>
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