Photogrammetric data processing is needed to generate a georeferenced
3D point cloud from the unordered, overlapping, and airborne
image collection of the surface. Existing Structure from Motion
(SfM) algorithms automatically extracted features in the images, for
example, contour lines, edges, and feature points. Homologous areas, interior
and exterior orientationswere computed in a bundle adjustment.
The Exchangeable Image Format (Exif) metadata from each digital
image further provided approximate values for the focal length and
image size.