Devising a method for determining the coordinates of an unmanned aerial vehicle by a network of three software-defined-radio receivers used in pairs

The object of this study is the process of determining the coordinates of an unmanned aerial vehicle. The main hypothesis of the study assumed that the use of a network of three Software-Defined Radio (SDR) receivers could improve the accuracy of determining the coordinates of an unmanned aerial vehicle. The use of SDR receivers in pairs would reduce the number of false bearings. A method for determining the coordinates of an unmanned aerial vehicle by a network of three SDR receivers when used in pairs has been improved, which, unlike the known ones, involves: – measuring bearings by each SDR receiver; – determining the pairwise angles of intersection of bearings; – determining the maximum of the pairwise angles of intersection; – determining a pair of SDR receivers for further calculations; – using the triangulation method for determining the coordinates of an unmanned aerial vehicle. The accuracy of determining the coordinates of an aerial object by a network of two SDR receivers has been assessed. It was found that: – the shape, orientation, and size of the error ellipses depend on the relative location in space of the SDR receivers and the unmanned aerial vehicle; – the size of the scattering ellipses is reduced by (20–40) % due to the use of information from the optimal pair; – in some cases, false switching of SDR receiver pairs is noticeable; – the pair (first SDR receiver – third SDR receiver) has the largest base from the considered options, that is, starting from a certain range, the angle of intersection of the bearings for this case is closest to 90°, the area of the scattering ellipses of coordinate measurement errors is minimal, which determines its choice; – when moving the unmanned aerial vehicle beyond the network coverage area of the SDR receiver pair, it is advisable to use another pair, this involves the use of a “chain” of SDR receivers