Weak target detection technology of passive radar on the navigation satellite signal

The passive radar detection system receives secondary reflection signal by the navigation satellite signal. The secondary reflection signal is too weak to detect the target. The method to improve the signal-to-noise ratio (SNR) of weak targets is proposed based on the accumulation algorithm. First, short-time correlation of the echo signal sequence is accumulated in the short-time coherence. Then long-time coherent accumulation is used in the frequency multiplication sequence. Finally, incoherent accumulation is used to detect weak target. By simulation, the SNR of target signal increases 8 dB than tradition method.