天波雷达短驻留时间下海杂波抑制的改进算法

在高频天波雷达的舰船目标检测中,为消除电离层变化带来的谱展宽效应,采用了短驻留时间下基于奇异值分解(SVD)的海杂波抑制算法.该算法对构造出的Hankel矩阵进行奇异值分解,将对应于海杂波分量的奇异值置零,再重新构造出数据序列,达到海杂波抑制的目的.相对于原有的迭代杂波对消算法,该算法无需估计众多参数及设置对消截止门限,并且可以获得更好的抑制效果.为了有效地识别分解后的海杂波与目标所对应的奇异值以避免错误对消,还提出了一种改进方案,可以在抑制前分辨出海杂波分量和目标所对应的奇异值,当回波目标的能量与海波处于相近量级以及多目标情况下,能够避免错误对消现象的出现.仿真结果验证了所提算法的有效性.

An Improved Ocean Clutter Cancellation Algorithm with Short Dwells in Sky-wave Radars

In order to eliminate the Doppler spread effect caused by ionospheric perturbation, an ocean clutter cancellation solution with short dwells was used to HF sky-wave over-the-horizon radar surface surveillance. A singular value decomposition (SVD) based ocean clutter cancellation algorithm and its improved version were introduced to the ship detection. By decomposing the Hankel matrix constructed from the observed signal, zeroing the singular values corresponding to ocean clutter components, and reconstructing the temporal sequence, the ocean clutter can be suppressed. Compared with the existing clutter cancellation algorithms, the proposed algorithm has better suppression performance and it need not estimate the associated parameters or set the iterative ending threshold. The paper also presented an improved scheme on the basis of the SVD algorithm, which can determine effectively different singular values corresponding to the ocean clutter and target signals before cancellation. The improvement algorithm can avoid the incorrect cancellation of target signal significantly in the case of multiple targets or ship echoes with powerful strength. Finally, simulations were given to illuminate the efficiency of the addressed algorithm.