MODELLING THE SURFACE GEOMETRY OF UNMANNED AERIAL VEHICLES, THE DESIGN OF WHICH CONTAINS ELEMENTS WITH DIFFERENT ELECTROPHYSICAL PROPERTIES

The current state of development of unmanned aerial vehicles requires the development of new methods for calculating their secondary radiation characteristics. This is due to the fact that the structure may have structural elements with different electrophysical properties. Currently, there are many approaches to modelling the surface of radar objects. The paper analyses these methods and identifies their advantages and disadvantages. On the basis of the analysis, an approach to modelling the surface geometry of unmanned aerial vehicles, the design of which contains elements with different electrophysical properties, is developed. The proposed approach contains elements of the faceted and ellipsoidal methods of modelling the surface of objects and is essentially a hybrid method. The surface is approximated by using sections of triaxial ellipsoids. Further, to calculate the secondary radiation of radar objects, each section of the triaxial ellipsoid is divided into separate triangular facets. The surface of the Orlan-10, RQ-4 Global Hawk, Matrice 200 quadcopter and Shahed-136 unmanned aerial vehicle, which is made according to the aerodynamic scheme of the “flying wing”, was modelled. The use of the developed approach to modelling the surface geometry of unmanned aerial vehicles, the design of which contains elements with different electrophysical properties, allows calculating the secondary radiation of objects, taking into account the presence of: object surface breaks; single-layer or multilayer fuselage and wing console construction; fuel tank and thin wire inside the wing console; perfectly conductive, dielectric or covered with radio-absorbing material internal equipment of an unmanned aerial vehicle. The application of the presented approach to modelling the geometry of the unmanned aerial vehicle surface can allow calculating the secondary radiation of electrically large objects in the high-frequency region and assessing the detection zones for radar devices of the corresponding wavelength ranges.