Abstract: Aiming at the insufficient accuracy of bearing-only location for the directional emitter，a multi-satellite distributed passive coherent location method was proposed.Firstly，the emitter was roughly located according to the strong signal received by the reference satellite.Then，the reference satellite signal was distributed to the adjacent satellite，and the cross-correlation search was carried out with the side lobe signal in the rough location range to solve the time difference.Furthermore，the precise location of the emitter was estimated by using the multi-satellite time-difference-of-arrival location method.Finally，the Cramer-Rao lower bound analysis of the proposed method was carried out.The method was verified by simulation experiments.Simulation results show that the method can effectively improve the location accuracy of the emitter when the SNR of weak signal ranges from -40dB to 0dB.The location error can quickly approach the Cramer-Rao lower bound.

Key words: multi-satellite distribution, passive coherent location, side lobe signal, cross-correlation search, Cramer-Rao lower bound