[gdal-dev] SRTM maps and altitude...

[Matt Klaric]

While you certainly can accomplish this using GDAL, you'll need to first
figure out which hgt file to open, then translate the geographic coordinate
to the image coordinate to know what pixel value to lookup.

An alternative solution is OSSIM (http://www.ossim.org/).  It has a
command-line app called ossim-height.  You can use it as follows:

$ ossim-height 45 10
Opened cell:  /srtm1/N45E010.hgt
MSL to ellipsoid delta:   39.049
Height above MSL:        37
Height above ellipsoid:  76.049
Geoid value:  39.049

You can setup a configuration file (see:
http://trac.osgeo.org/ossim/wiki/ossimElevationSetup) that points to your
directory of hgt files and OSSIM will figure out which file is needed for
your query.

If you're needing to embed this in an application of yours, you can use the
OSSIM API to accomplish the same thing.  Check out the source for
ossim-height for an example of how to do this.

--Matt


On Fri, Jun 11, 2010 at 9:33 AM, Gianni Olivieri
<gianni.olivieri at gmail.com>wrote:

> Hallo,
>
>    I need to extract the altitude of a GPS coordinate from a serie of
> HGT (SRTM or DEM) (I've download the entire Eurasia...
>
> So, for example, If I have a directory with all htg file and I'd like
> to know the altitude of this coords:
>
> 48°01'35.89" N
> 8°23'51,86" E
>
> how can I preceed?
>
> The elevation in that point is: 761m (google earth result)
> I'd like to have a similar results.
>
> Best regards
>
>
>
> --
> Gianni Olivieri
> gianni.olivieri at gmail.com
> _______________________________________________
> gdal-dev mailing list
> gdal-dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>
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