DoA techniques in UAV detection with DVB-T based Passive Radar

In this paper, the study of different target Direction of Arrival (DoA) techniques for Passive Radar (PR) exploiting Digital Video Broadcasting signals is carried out. Conventional Beamforming (CBF) algorithms based on signal covariance matrix estimation are compared to Amplitude-Comparison (ACM) and Phase-Comparison (PCM) monopulse techniques to find the solution that provides higher accuracy for Unmanned Aerial Vehicles (UAV) detection and localization. DoA algorithms were performed in the transformed domain defined by the cross ambiguity function, and were evaluated using real radar data acquired by a PR demonstrator developed at the University of Alcalá, which used a Uniform Linear Array (ULA) in the surveillance channel. CBF techniques were designed considering the whole ULA, whereas monopulse ones were implemented using a reduced sub-array. Results proved that ACM and PCM are suitable for target angle of arrival estimation in PR systems. However, CBF techniques provide higher estimation accuracy, being the proper DoA estimation method of those studied for UAV localization in PR scenarios.