I've heard it is possible to use NASA elevation model to determine approximate elevation at (lat;lng) point. This might be really useful for my upcoming project since Google Elevation API has weird limitations...and I don't really like USGS Elevation Query Web Service because of its speed. I'd want to have elevation query tool/framework on local computer, which works with local file.
I did my homework, and found GeoTiff files might be downloaded with no problem. But I've failed to find any useful documentation or framework.
Can somebody share a link to the specs, or example or tutorial on how to work with GeoTiff files? Is there any frameworks to get this done (.NET,Java,C++,C - doesn't really matter)?
According to what I see in the GeoTiff files and its header files, I assume each tiff represents small area and pixel color (16 bit value) indicates elevation there in meters. Is that correct?