Terrestrial photogrammetry
As terrestrial photogrammetry surveying terrestrial objects is absorbed at the surface measurement images called. It was the first method of photogrammetry at the turn of the century , when aerial photographs were not yet known , and at that time it was also used for topographical terrain mapping . Today, however, the latter is mainly done using satellite images or aerial photogrammetry .
Today, terrestrial measurement images only measure objects up to about 100 m in length, especially buildings and facades ( architectural photogrammetry ), quarries or gravel pits , furthermore to secure evidence of traffic accidents and, in some cases, to add detailed maps to small landforms or rock drawings of steep mountain slopes.
The objects are measured using two or more “ photograms ” that are recorded by special cameras set up on surveying tripods . The camera positions are mutually (locally) measured or determined in a survey network . The mutual orientation of the measurement images takes place through so-called control points . For the evaluation, identical, clearly visible points are selected in the images and their coordinates are determined using geometric cutting methods .