基于干涉合成孔径雷达测高原理的雷达散射截面测试杂波抑制方法

Clutter Reduction Method for Radar Cross Section(RCS)Measurement Based on InSAR Principle

针对近场扫描体制电磁散射测量中的杂波抑制问题,提出了一种基于干涉合成孔径雷达测高原理的高度向滤波方法.该方法首先通过在不同高度下的天线两次直线扫描,得到目标的两幅雷达二维像;从雷达图像中提取散射中心的幅相数据后,再利用两次测量得到的散射中心相位差并结合扫描天线高度信息,解算得到该散射中心的高度;根据被测目标的高度范围,设置高度向滤波器,滤除目标高度区以外的散射源杂波;滤波后可以重构得到目标的雷达散射截面,实现抑制杂波、提高测量精度的效果.仿真结果表明,使用该方法处理后目标RCS均值误差小于1 dB.从试验结果来看,使用该方法可从与目标散射量值接近的强杂波背景环境中准确提取目标散射中心.

In order to reduce the clutter in near-field electromagnetic scattering measurement,a clutter filtering method in height dimension based on InSAR principle was proposed in this paper.Firstly,two radar two-dimensional images of the target are obtained by twice linear scanning of the antenna at different heights.Then,the amplitude and phase of scattering centers were extracted from the radar images data,and the height of the scattering center can be calculated by using some information,including the phase difference of the scattering center and antenna height between the two measurements.Afterwards,according to the target height range,the filter in height dimension was set to reduce clutter outside the target height range.Finally,the RCS of the target was constructed after filtering so as to reduce the clutter and improve the accuracy of RCS data.The result of simulation demonstrates that the mean RCS error is reduced to within 1 dB with applying the proposed method.And the scattering centers of an aircraft model are accurately extracted from a strong clutter experiment environment,which has the equivalent scattering intensity with the target.