Photogrammetry is a technique allowing measurements of features visible on photographs taken from different points of view.

This technique is based on stereoscopy.

In airbornb photography, we don't use 2 camera placed at a fixed distance, but rather images acquired from the same camera, at different positions along the flight line.

The area covered by 2 sucessive (and overlapping) photos can be seen in 3D:

Photogrammetry is based on very accurate measurement of offset observed between 2 views of the same object.