Target height and multipath attenuation joint estimation with complex scenarios for very high frequency radar

Abstract

Low-angle estimation for very high frequency (VHF) radar is a difficult problem due to the multipath effect in the radar field, especially in complex scenarios where the reflection condition is unknown. To deal with this problem, we propose an algorithm of target height and multipath attenuation joint estimation. The amplitude of the surface reflection coefficient is estimated by the characteristic of the data itself, and it is assumed that there is no reflected signal when the amplitude is very small. The phase of the surface reflection coefficient and the phase difference between the direct and reflected signals are searched as the same part, and this represents the multipath phase attenuation. The Cramer-Rao bound of the proposed algorithm is also derived. Finally, computer simulations and real data processing results show that the proposed algorithm has good estimation performance under complex scenarios and works well with only one snapshot.

摘要

由于多径效应的影响, 甚高频雷达低角估计是雷达领域难题之一, 尤其是在反射条件未知的复杂情况下, 低角估计更难解决。针对这一问题, 提出一种目标高度和多径衰减联合估计算法。该算法首先利用数据本身的特性估算反射系数幅度, 当该幅度估计值很小时, 认为没有反射信号, 然后将反射系数的相位和直达信号与反射信号之间的相位差当作同一部分, 即多径相位衰减, 并对其进行搜索。推导了该算法的克拉美罗界。最后, 计算机仿真和实测数据处理结果表明, 该算法在复杂场景下具有良好估计性能, 并且在仅有单次快拍的条件下仍能较好地工作。