[gdal-dev] Unknown file type

[Frank Warmerdam]

Greg Ederer wrote:
> Hi,
> 
> I am a GDAL newbie.  I just got handed a group of files with the 
> following description:
> 
> description of the data
>      1)  content:
>        rain  ==   10 day precipitation analysis by merging      
>                   GTS gauge observations and  3 kinds of satellite 
> estimates
>                   (GPI,SSM/I, and AMSU)
>       2)  coverage:
>        -40.00S -- 40.00N Northward;
>         20.00W -- 55.00E Eastward        751 grid points in east - west 
> direction
>        801 grid points in south - north direction
> 
>    3)  resolution:
>        0.1 deg lat x 0.1 deg lon
>        dekad
>    4)  missing values
>        -999.0
> 
> I'd like to read and manipulate these files using GDAL.  When I run 
> gdalinfo, I get something like the following:
> 
> Macintosh-4:RFE_dekedal gregederer$ gdalinfo 10day_precip.bin.1999121
> ERROR 4: `10day_precip.bin.1999121' not recognised as a supported file 
> format.
> 
> gdalinfo failed - unable to open '10day_precip.bin.1999121'.
> 
> I suspect that GDAL requires some additional metadata in order to read 
> these files.  Any suggestions?

Greg,

Assuming this is a raw binary file you can write a VRT "raw" description
for it based on:


   http://www.gdal.org/gdal_vrttut.html

Read down in particular to the ".vrt Descriptions for Raw Files" section.

There are also several other methods for accomplishing something similar.

In your case I'd assume the file is 751x801 x 1band x Float32 with
ImageOffset=0, PixelOffset=4, LineOffset = 3004 and ByteOrder LSB.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent