Direct Position Determination Based on Passive Synthetic Aperture for Coherent Receivers

Source localization is a widely used technique in various applications. Unlike two-step location methods, which first calculate intermediate parameters such as time delay and Doppler shift, direct position determination methods estimate the source position directly from the received signals, resulting in superior accuracy at low signal-to-noise ratio (SNR). For multiple moving receivers, this paper proposes a novel direct positioning determination method based on the principle of passive synthetic aperture for pulse signal sources. Inspired by matched filter receivers that follow the maximum output SNR criteria, the objective cost function of the proposed method is established through the coherent superposition of received signals. The coherent Cramér-Rao lower bound (CRLB) of the source location is deduced for the proposed method. Simulation results demonstrate that the proposed method significantly improves the location accuracy and applies to multiple radiation sources situations. Furthermore, the computational complexity of the proposed method is analyzed, which slightly outperforms traditional direct positioning determination (DPD) methods in terms of calculation efficiency.