一种改进的米波雷达低仰角处理算法

Improved Algorithm for Meter-wave Radars to Target at Low Altitude

由于多径效应的存在，使得米波雷达在低仰角工作时接收到的回波是两组相干信号，即直达信号和反射信号的矢量叠加。提出了一种米波雷达在低仰角环境下DOA（波达方向）估计的新方法，先对各子阵的接收数据进行线性变换，然后对线性变换后的数据和实测数据的差分结果应用阵列旋转不变性实现米波雷达低仰角的波迭方向估计．算法对信号所处环境不敏感，可以有效地克服多径效应，而且运算量小。理论分析和计算机仿真都表明新算法的优越性。

The echoes of meter-wave radar received are coherent signals consisted of direct and reflected signals due to the multipath effect at low elevation angles. A new method that couM estimate the DOA （direction-of-arrival） of a target under low-angle condition was proposed Linear transform was applied to the received data of every subarray firstly. Difference operation was performed to received data and transformed data secondly. Finally applying super- resolution algorithm to the result from step two, the DO,4 of a target for meter-wave radar could be obtained using rotational invariance techniques at low altitude. This method is not sensitive to the signals environments and can overcome multipath effect effectively. Theoretical analysis and simulation results demonstrate the merits of the new algorithm.