oa Methodology of 3D Modeling Based on Aerial Images from a Drone with Simplified Geodetic Reference

The use of UAV-photogrammetry for obtaining digital 3D models has become widespread, in particular, in such areas as technical inspection, assessment of damage to buildings and structures (in particular, as a result of emergency and war situations), control of earthworks, etc. In part of these applications, the modeling of the territory or individual objects is carried out in order to determine their geometric parameters - such as areas, volumes, mutual distance between points. That is, the 3D model must be geometrically accurate enough, and the accuracy of its spatial position (in geodetic space) is secondary. Therefore, we pay attention to the research of the photogrammetric technology of processing aerial photographs obtained from UAVs, which allows to ensure the creation of 3D models of sufficient accuracy, first of all, for environmental and engineering applications. At the same time, we aim to minimize the use of expensive and difficult-to-operate geodetic equipment. To achieve this goal, we set up an experiment where we test the quality of a 3D model of a construction site with a pit. The model was created without the use of ground reference points and exact coordinates of the projection centers of aerial photographs. Reference information is the measurements of inclined distances between individual points on the site. Thus, the approach proposed here allows modeling of objects in an arbitrary geodetic orientation, but in the correct horizontal and vertical scales.