低重频雷达回波准最大似然速度估计

Quasi-Maximum Likelihood Velocity Estimation Using Low PRF Radar Echoes

传统算法处理脉冲雷达的回波信号时,对于高速运动目标,往往会产生严重的速度模糊问题。对相参脉冲回波信号的距离-速度模糊函数进行分析,发现其盲速旁瓣在速度真值处达到最大值,在真值两侧的旁瓣对称逐渐减小。利用这个性质,提出了一种基于最大似然估计的速度粗估计算法,通过搜索盲速旁瓣的峰值位置,该位置对应的速度即为目标速度估计值。本方法利用少数脉冲回波,通过有限次数的计算,就能够得到具有一定精度的测速结果。仿真结果证明了本算法的有效性。

In dealing with the echo signals of pulsed radar,the traditional algorithms often face serious velocity ambiguity problem for high-speed moving targets.The range-velocity ambiguity function of the coherent pulsed radar echoes is analyzed.A property is found that the amplitudes of blind speed sidelobes reach the maximum when the reference velocity equals to the true velocity and gradually decrease on both sides of true velocity.According to this property,a maximum likelihood estimation based velocity coarse estimation method is proposed.Through searching the peak position of the blind speed sidelobes,the corresponding velocity value of the peak is the estimate of the target velocity.This method can achieve a relative precise velocity measurement result using only a few echo pulses through a limited number of calculations.The simulation results show the effectiveness of the proposed algorithm.