基于修正Rife算法的脉冲回波相参积累算法

针对目标径向运动导致回波在波门内出现距离走动的情况,提出了一种针对径向匀速运动目标回波信号长时间相参积累的方法。该方法根据傅里叶变换的时移性质——不同时刻回波频谱相关序列的频率包含了各回波到达的时间延迟,通过修正Rife算法估计此时间延迟,最终确定并补偿各个回波的距离走动分量。仿真结果表明:提出的方法可以有效补偿各回波间的距离走动;信噪比低至-6dB时,算法的性能即可达到最优;补偿后积累信号的信噪比可以达到理想积累情况下的93%。

A Coherent Pulse Echo Integration Algorithm Based on Modified Rife Algorithm

This paper presents a method for long duration coherent integration of target echo signals of radial movement at even velocity to compensate for range migration of echo in the wave gate as a result of radial movement of an object. Considering the property of time shifting of DFT (Discrete Fourier Transform) the frequency of coherent series of echo spectrum at different moments contains delay of each echo range misalignment is compensated with modified Rife algorithm by estimating the quantity of radial range migration. Simulation results indicate that the proposed method effectively compensates for inter echo range migration. Performance of the algorithm reaches the best at the low SNR (Signal to Noise Ratio) of 6 dB. The SNR of the integrated signal following compensation could reach 93% of ideal integration.