The master's thesis entitled »Influence of the quality of ground control point coordinates on photogrammetric products« covers the definition of coordinates for photogrammetric ground control points and control points using different of GNSS methods. The field measurements included a GNSS static measurement lasting several hours, several repetitions of RTK measurements and a flight over the area with a remote-controlled aircraft system. The observations of the several-hour static measurement were analysed with different parameters – changing minimal elevation angles, models of tropospheric refraction, by using different ephemerides, linking to different continuously operating GNSS reference stations and using observations of different occupation durations. The positions of the points obtained by analysing the several-hour static measurement were compared with the positions defined by the RTK method. The positions of the points obtained from a relative analysis of the GNSS static measurement were compared with the positions defined by the precise point positioning (PPP) absolute method with different web applications. The input data for photogrammetric analysis in which the photogrammetric point clouds, DSMs and orthophotos were made, were the photographs of the study area, taken by the remote-controlled aircraft system, and the coordinates of the ground control points, defined by the GNSS methods of measurement of different accuracies. The photogrammetric products were produced in the program 3Dsurvey and analysed by assessing accuracy in two ways. In order to evaluate the absolute accuracy of the products, we used points, fixed with GNSS static measurement lasting several hours as a control point, the relative accuracy was made by comparing the reference products.
|
