多星分布式无源相干定位方法

针对方向性辐射源信号主瓣波束窄测向定位精度不足的问题，提出多星分布式无源相干定位方法。首先，根据参考星接收到的主瓣强信号对辐射源位置进行粗定位，并根据粗定位信息对频移进行补偿；随后，将参考星信号分发至临近卫星，在粗定位范围内对相干星接收到的旁瓣弱信号进行互相关搜索，解算时差信息；然后，采用多星时差定位体制估计辐射源精确位置；最后对提出算法进行了Cramer-Rao下界分析，并通过仿真实验对算法进行验证。仿真结果表明，算法在弱信号信噪比(SNR在-40～0 dB)的情况下，定位误差能够快速逼近Cramer-Rao下界，并且能够有效提高辐射源的定位精度。

Research on multi-satellite distributed passive coherent location method

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.