一种解大旋翼类雷达目标微Doppler模糊的方法

A Method to Resolve Micro-Doppler Ambiguity for Targets with Big Rotating Blades

在单通道模式下,当雷达目标旋转半径比较大时,脉冲重复频率与微多普勒带宽之间可能会出现欠采样的情形,导致在时频面上发生微多普勒混叠,从而不能得到完整的微多普勒信息。针对此问题,提出了一种基于双通道干涉处理的解大旋翼类雷达目标微多普勒模糊的方法。文中详细推导了该模式下此类目标引起的微多普勒频率和微多普勒带宽的参数化表达式,分析表明其微多普勒带宽受一个正弦因子的调制而显著减小,从而使其满足香农采样定理,避免了微多普勒模糊现象。最后,数值仿真表明了理论推导和所述方法的正确性。

Under the configuration of single-channel, if the radius of the rotating blade is comparatively big, the relationship between the pulse repetition frequency （PRF） and the bandwidth of micro-Doppler will not follow the Shannon sampling theorem, i.e. sub-sampling occurs, which would lead to the phenomenon of micro-Doppler ambiguity. To solve this problem, a method for resolving the micro-Doppler ambiguity for targets with big rotating blades based on the dual- channel ATI technique is presented. The mathematical expressions of micro-Doppler frequency and the bandwidth of micro- Doppler are deduced in detail. The analysis indicates that the bandwidth of micro-Doppler under this configuration is modulated by using a sinusoidal function, which makes it much smaller than that of the single-channel situation, so the Shannon sampling theorem is satisfied and the whole time-frequency distribution without ambiguity can be gained. Finally, the simulation results are given to prove the validity of the presented method.