CREATING PHOTOTRIANGULATION NETWORKS IN AGISOFT PHOTOSCAN
The paper describes the stages of creation and adjustment of phototriangulation networks in Agisoft Photoscan, which includes “photo alignment”, “georeferencing” and “optimization”. These terms were introduced by the program developers and are not used in photogrammetry at all. So-called camera calibration is considered in detail by developers, but for the procedures listed above it is not specified in what way and by what formulas they are performed, although software users have the right to know what is the algorithm for solving the problem and what methods are used when performing this or that operation. In our work, we built phototriangulation networks without ground control points, based only on the coordinates of the photographing centers, obtained from GPS data and with a different number of control points. Since the GPS data was of low accuracy, the accuracy of the results obtained in networks without control points was low as well. In our opinion, there should not be less than five control points in the network. After evaluating the accuracy of the results obtained, the scales and height of the relief section of the created plans were determined.