Comparison of 3D models of mass graves created on the basis of aerial survey data in 1944 and 2015

The purpose of the research is to determine the location of the mass graves of Jews in Vynnyky near Lviv based on eyewitness accounts and archival aerial photographs of 1944, creation of the DEM of the territory of burials on aerial photographs of 1944 and on the basis of aerial survey from UAV in 2015 and comparison of created models. To accomplish this task the workflow is proposed, which provides successive steps. This workflow includes the following stages: creation of an orthophoto map and elevation map according to aerial survey data of 2015; elaboration of a stereo pair of German aerial photographs of 1944 and obtaining contour lines of the relief for the war period; interpretation on archival aerial photographs of the territory of the mass grave according to the approximate location indicated by eyewitnesses and determination of its area; construction of vector maps on the territory of the mass grave for 1944 and 2015; analysis of the DEM of 1944 and 2015 in the place of the mass grave and drawing conclusions. As a result of processing the input data, the mass grave was clearly interpreted and it was determined that the difference in height of its boundaries for 1944 was from 20 to 36 centimeters, the difference in height for 2015 on the part of boundaries of the grave was from 15 to 20 cm. Height differences are observed in the rest of the territory, which belongs to the mass grave and beyond. From this we can conclude that after many decades, despite human intervention and agricultural plowing, the elements of soil subsidence in the grave are still preserved.