WORLD FOR CIVIL

Photogrammetry

Photogrammetry is the art and science of obtaining reliable measurements by photography (metric photogrammetry) and qualitative evaluation of image data (photo interpretation). It includes use of terrestrial, close-range, aerial, vertical, oblique, strip, and space photographs along with their interpretation.

Scale formulas are as follows:

Photo scale=ab/AB=f/(H-h₁)

where f =focal length of lens, in (m)

H =flying height of airplane above datum (usually mean sea level), ft (m)

h1 =elevation of point, line, or area with respect to datum, ft (m)