I have a SRTM DEM and need to find whether it has voids or gaps in the data.
The DEM will have a nodata value that means there is a void (no information there). Load the .hgt file into QGIS / Arc, look at the layer properties, to find out what it is. Visually, you could:
- Make the layer completely black.
- Set the nodata value to be transparent (should be automatic).
- Look for voids.
Programmatically, you could
- load the raster to an array and
- count nodata values.