AOA Measurement Processing for Positioning using Unmanned Aerial Vehicles

This paper considers 3D angle of arrival (AOA) measurements processing model for positioning a transmitter by cooperation of flying segment based on receiver station aboard Unmanned Aerial Vehicle (UAV) with terrestrial segment including stationary ground receiver station and confirms its practicability for handling Non-Line-Of-Sight (NLOS) problem. Positioning with UAVs is especially relevant for search and rescue (S&R) operations in heterogeneous terrain with inherent reflections resulting in primary measurements distortion. NLOS problem was thoroughly investigated for 2D scenarios with stationary ground receiver stations, however for 3D UAV based positioning this is a topic of ongoing research. In this paper relevant works for UAV based positioning were analyzed to explore advantages and shortcomings of AOA technique. The contribution of the current research is the refinement of model for positioning of radio transmitter with one stationary ground and one flying UAV based receiver station using AOA measurement processing, its performance evaluation with handling AOA noise in NLOS conditions, and comparison with Cramer-Rao lower bound (CRLB). Resulting estimates agree with known results and validate possibility to locate the transmitter in NLOS scenarios with just two stations when AOA deviation is less than 10 degrees.