STL employs two
methods for DEM generation. We use the
information from topographical maps at scales
from 1:10,000 to 1:250,000 depending on
availability and the required resolution to derive DEMs.
For those areas where contour maps are not
available, we employ high resolution satellite
imageries, Aerial Photographs or Land surveying methods to generate
spot height data at regular intervals and then use to
produce the DEMs.