Analysis of SNR loss for passive coherent location radar

PCL radar detects moving targets by using ambiguity function, which is based on the cross correlation coherent process of the direct-path signal and echo signal. Thus, the direct-path signal is important to system performance in passive radar based on extra illuminator. In this paper, we discuss how the SNR of the direct-path signal leads to SNR loss, and analyze the integration gain versus long integration time. The paper presents theoretical analyses accompanied by numerical results based on simulated data, which provide the theoretical base of passive radar.