Method of determining the set of drone positions to cover maximum visibility of the terrain

One of the important tasks when conducting aerial photography by drones is a preliminary estimation of the drone's trajectory, both from the point of view of route optimality and from the point of view of providing a maximum view of the terrain with the drone's camera. These tasks do not have an exact solution, so in practice they are solved using optimization methods. In this case, there is a need for effective preliminary selection of key points of the drone's route, which evenly cover the terrain. This will improve the overview of the obtained route. The paper proposes an approach to determining the initial set of points that provide the maximum overview of the terrain. The terrain is set in the form of a polygonal model. The basis of modeling is the solution of the problem of covering the set by splitting the set of survey candidate points into a regular grid and representing this grid in the form of a spatial hash table to speed up the search. The proposed approach allows you to determine the necessary degree of discretization of the parameter space and the minimum number of points-positions of the drone, which provide the maximum overview of the terrain. This approach involves the following steps: emission of rays from each polygon of the geometric terrain model; splitting into a regular grid and spatial hashing of the obtained set of potential points of view; sort a hash table by its weighting factors; iterative selection of the set of points providing the maximum overview of the terrain from the sorted set. The developed algorithm provides the selection of the route points of the drone with a given coverage factor. The influence of the main parameters of the method, which include the spatial resolution of the discretized grid and the minimum number of iterations of the algorithm to achieve a given coverage coefficient, is studied.Keywords: drone, aerial photography, route planning and optimization, task of covering the set, set of points, regular grid, spatial hash table, maximum terrain overview.