Did You Know?
Photogrammetry refers to the process of recording, interpreting and measuring from photographic images.
For aerial photogrammetry we mount our camera in our aircraft and point vertically towards the ground. As the aircraft flies along a flight path, multiple overlapping photos of the ground are taken. These photos (called stereo photos) are processed using special software and hardware that lets an operator see two photos at once in a stereo view. This means that the operator can measure the ground surface and other objects in three dimensions.
Digital Elevation Models (DEM) such as digital surface models (DSMs) and digital terrain models (DTMs) can to be derived from stereo imagery.
A person specialised in undertaking this work is called a photogrammetrist.