Direction of Arrival Estimation Techniques for Passive Radar based 3D Target Localization

This paper presents a comparative analysis of direction of arrival (DOA) estimation techniques for the application in a linear antenna array of a passive bistatic radar (PBR). State of the art and emerging DOA algorithms were investigated in order to identify techniques that achieve optimum accuracy performance. The viability is demonstrated with experimental data obtained from a field trial with a PBR that exploits illuminations by the digital transmissions standard DVB-T2. The trial focused on air surveillance in the controlled traffic region (CTR) of an international airport. A target localization scheme was developed, with special emphasis on accurate estimation of the aircraft height, were the multistatic nature of a single frequency network (SFN) is exploited. As a consequence, the PBR is able to receive and process multiple time difference of arrival (TDOA) measurements from a single target within the same signal. This in conjunction with the system's DOA capability allows to accurately estimate 3D positions of air targets within the CTR.