Photogrammetric Methods

The main purpose of photogrammetry is to define the quantitative parameters of objects using images taken by photographic or digital cameras. The typical output of photogrammetry is a map or three-dimensional (3D) model of some real object or scene. Photogrammetry is widely used to compile topographic maps of Earth's surface.

Photogrammetry is based on principles of ste-reometry—a branch of geometry that studies the projections of 3D objects into 2D space; in particular, photogrammetry deals with the appearance of real 3D objects in two overlapping photographs (image stereopair). The fundamental geometric principle used by photogrammetry is triangulation. By taking photographs from two (or more) different locations, so-called lines of sight can be developed from each camera to points on the object. These lines of sight are usually ...