A Receive-Coherent Detector of Moving Target for Airborne Distributed Coherent Aperture Radar under Random Phase Errors

Airborne Distributed Coherent Aperture Radar (ADCAR) benefits from the signal coherent synthesis of multiple transmit-receive (TR) pairs echoes to improve signal gain and detection performance significantly. However, the independent partitioning of airborne distributed radars tends to introduce complex random phase errors that will severely reduce the target detection performance for the received coherent synthesis. In this paper, we first consider the receive-coherent model of ADCAR under random phase errors and introduce the Von-Mises distribution to model the random phase error. Then, a receive-coherent Generalized Likelihood Ratio Test (GLRT) detector (RCD-VEM-G) based on the expectation maximization (EM) algorithm is proposed according to the Von-Mises distribution model, which iteratively solves for the unknown parameters under the alternative hypotheses by the EM algorithm to achieve the GLRT for the target. Simulation results show that the proposed RCD-VEM-G detector ensures better detection performance under random phase errors for different shape parameter models and outperforms the conventional target detector, proving the effectiveness of the proposed method.