DOA Estimation for Passive Radar Under the Scene Where Target Echo Is Partially Correlated

In this paper we consider that there is a position difference between the reference antenna and surveillance array in a passive radar system. In this scenario, the target echo in the reference channel and surveillance array is partially correlated instead of completely correlated. Due to the correlation of target echo, adaptive clutter cancellation will influence the target steering vector and cause direction of arrival (DOA) estimation bias. To solve this problem, we establish the array signal model where the target signal in the reference channel and surveillance channels is partially correlated and analyze the influence of the adaptive clutter cancellation on the target steering vector. Then, a DOA estimation method suitable for this scenario is proposed to correct the DOA bias. Simulations and real radar data show that the proposed method can correct DOA bias in this scene, thereby improving the location accuracy of passive radar.