[gdal-dev] lat lon matrix tables to geotif

[Frank Warmerdam]

On 11-02-15 01:20 PM, Nikolaos Hatzopoulos wrote:
> So we have three tables:
> one matrix for latitude values
> one matrix for longitude values
> one matrix for our data values
>
> all the matrix have the same dimensions
>
> how we can convert these three tables to geotif using gdal??

Mikos,

This is a georeferencing method I refer to as "geolocation grids".  It is
not a supported organization in GeoTIFF so there is no way to produce
a GeoTIFF with the above data where the meaning of the latitude and longitude
values will be well understood.

If you want to use the resulting geotiffs in non-GDAL applications I
think you are best just turning each matrix into a separate TIFF file
with appropriate file names to suggest the meaning to and end user.

Another option is to just rectify the image data into a normal north
up rectified grid and write that to GeoTIFF.  Such an output would be
easily exploited in any GeoTIFF reading application.

It also is possible to use metadata to associate the latitude and longitude
as geolocation grids within a GeoTIFF file in a way that some GDAL
applications (like gdalwarp) could take advtange of.  This requires setting
up very specific metadata items to relate the data.  The metadata required
(for geotiff or other formats) is listed in RFC 4:

   http://trac.osgeo.org/gdal/wiki/rfc4_geolocate

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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