EFFECTS OF RADIO WAVE PROPAGATION IN URBANIZED AREAS ON UAV-GCS COMMAND AND CONTROL

In an urban environment, the linkage between UAVs and ground control stations are subjected to multipath interference due to reflection, diffraction, and scattering between the transmitter and receiver. Severe multipath can result in a nearly complete loss of command signals, which can limit the UAV’s operational area or even cause a loss of the vehicle. This paper examines the propagation of RF signals through an urbanized area using a ray-tracing computational electromagnetics software package. Several scenarios were developed to approximate actual operational situations. Given the UAV’s transmitter power and other system parameters, the signal levels are computed on a grid of specified observation points. Variations in the simulation included observation point locations, building material composition, building density, UAV operating altitude and frequency, number of deployed UAVs and their locations, and theoretical ray bounce considerations. Based on a large number of simulations several guidelines for operating a UAV in a dense urban environment are suggested, such as how to select an optimum altitude and the potential use of “urban canyons ” for communications. 50 I