中文摘要：

针对散射信号的强弱直接影响接收效果的问题，通过对GPS散射信号的仿真，探讨了电磁波不同入射角度时的散射特性，比较了电磁波在不同散射截面积、不同信噪比情况下对最大距离积的影响．分析显示前向散射可获得较佳的信号接收效果，通过选取最佳接收卫星可扩大无源探测的范围．

英文摘要：

The strength of scattering signals affects reception directly. Though simulation of scattering signals is studied the object＇s radar cross sections under different bistatic angles, and compared the influence of different radar cross sections, and the signal-to-noise ratios to the maximum detection range. The analysis showed that forward scattering makes good reception, and GPS passive detection range can be enlarged by selecting the optimum satellites.