海面目标ISAR成像的杂波仿真与抑制

对海面目标进行ISAR成像时,会受到海杂波的影响。文中分析了ISAR成像中海杂波的统计分布模型、时间相关特性和空间相关特性,给出了一种相参杂波的仿真方法,并提出了一种ISAR中的杂波抑制算法。仿真算法利用球不变随机过程产生K分布相参杂波,并通过两次线性变换,使得杂波满足给定的时间和空间相关特性。为抑制ISAR信号中的海杂波,本文应用恒虚警检测技术,在预处理的ISAR像上设定一个适当的门限,以保留散射点信号、滤除杂波。最后,仿真结果证明了该算法的有效性。

Clutter Simulation and Compress of ISAR Imaging in Targets on Sea Surface

When an inverse synthetic radar(ISAR) imaging the targets on sea surface,sea clutter may decrease the imaging performance.In this paper,we analyze the clutter probability distribution function,and examine the temporal and spatial correlation properties of the clutter.A sea-clutter simulation method is presented,and an algorithm to reject the sea clutter in ISAR signals is proposed.In the simulation method,the K-distribution coherent clutter is generated by spherically invariant random process,followed by two linear transformations,the two dimensional clutter with the given temporal and spatial correlation is obtained.In order to improve the ISAR images quality in presence of sea clutter,we set an appropriate threshold in the ISAR images through the constant false alarm rate processing,hence the scatter signals are retained and sea clutter is rejected.Finally the simulation results demonstrate the effectiveness of the algorithm.