外辐射源雷达互模糊函数的两种快速算法

Two Fast Algorithms of Cross-Ambiguity Function for Passive Radar

针对外辐射源雷达(无源雷达、被动雷达)利用互模糊函数测量时延差和多普勒频移的运算量大,直接计算难以满足系统实时性要求的问题,本文提出了外辐射源雷达互模糊函数的两种快速算法:分级抽取FFT算法和预加权分级抽取FFT算法.分级抽取FFT算法降低了抗混叠滤波器的阶数,明显地节省了计算量和存储量;预加权分级抽取FFT算法使第一级滤波的乘法运算在时延的循环外进行,进一步提高了计算效率,代价是存储量有所增加.实测结果表明本文所提两种快速算法有效地提高了计算效率.

The computational burden of cross-ambiguity function is very large for measuring the time delay difference and the Doppler frequency shift of passive radar, which is difficult to meet the real-time requirements by the general algorithms. This paper proposes two fast algorithms of cross-ambiguity function for passive radar：the multi-stage decimation FFT algorithm and the pre-weighting multi-stage decimation FFT algorithm. The multi-stage decimation FFr algorithm decreases the length of the anti- aliasing filters and save the computational amount and the storage. The pre-weighting multi-stage decimation FFT algorithm avoids the cycle of the ftrst-stage filter multiplication in different time delays and further increases the computational efficiency at the expense of the large storage. Experimental results show that the proposed algorithms can effectively increases the computational efficiency.