基于离散频率编码的PD雷达二维解模糊方法

针对脉冲多普勒雷达在中脉冲重复频率下同时存在距离模糊和多普勒模糊问题, 提出了一种基于正交离散频率编码(discrete frequency coding, DFC)波形解二维模糊的方法。基于雷达循环发射的一组正交DFC信号, 在回波脉冲压缩过程中, 利用信号正交性进行距离模糊区域的分离, 完成距离解模糊。通过多普勒模糊数遍历补偿以及与keystone后相参积累结果对比, 确定正确的多普勒模糊数, 完成多普勒解模糊。经过Keystone处理后, 可以进行整个驻留时间的相参积累, 提高回波在低信噪比情况下的目标检测及参数估计能力。同时考虑了DFC信号的多普勒敏感性问题, 在精确匹配滤波过程中补偿了脉内多普勒的影响。仿真实验验证了所提方法解二维模糊的有效性以及低信噪比检测能力。

Two-dimensional ambiguity resolution method of PD radar based on discrete frequency coding

Aiming at the problem of range ambiguity and Doppler ambiguity in pulse Doppler radar at medium pulse repetition frequency, a method of applying orthogonal discrete frequency coding (DFC) waveforms to airborne PD radars is proposed. Based on the radar cyclically transmits a set of orthogonal DFC waveforms the orthogonality of the signal is used to separate the range ambiguity area and complete the range ambiguity resolution in the process of echo pulse compression. Through the Doppler ambiguity number traversal compensation and the comparison of the keystone coherent accumulation results, the correct Doppler ambiguity number is determined and the Doppler ambiguity resolution is completed. After Keystone processing, the coherent accumulation of the entire dwell time echo signal can be carried out to improve the detection and parameter estimation performance. At the same time, this paper considers the Doppler sensitivity of the DFC signal, and compensates the influence of inter-pulse Doppler in the process of precise matched filtering. Simulation experiments verify the effectiveness of the proposed method.