RCS测量中目标与金属支架间的耦合散射研究

Research on interactions between target and metal pylon in RCS measurement

在采用低散射金属支架的目标雷达散射截面(radar cross section,RCS)测量中,被测目标与低散射金属支架之间的耦合散射效应是影响测量数据不确定度的重要因素。以RCS测试中常用的短粗圆柱定标体和飞翼外形隐身飞机模型为被测目标,重点研究目标与金属支架间的表面波型与多次反射型两种主要耦合散射机理。采用一维高分辨距离像、时频分析、二维逆合成孔径雷达成像等技术,分析了被测目标与金属支架之间不同类型耦合散射的形成机理,并据此提出了相应的消除方法。数值计算与仿真结果验证了本文方法的有效性。

In radar cross section(RCS)measurement using a low RCS metal pylon,the effect of interactions between the target under test and the metal pylon might be a significant factor degrading the accuracy of measurement data.In this paper,a squat cylinder calibrator which is widely used in RCS measurement and a wing-typed stealth aircraft model are respectively taken as the targets under test.The two major mechanisms of the target-pylon coupling scattering,i.e.,the surface wave type and the multiple reflection type are studied.Using one-dimensional high-resolution range profiling,time-frequency analyzing and two-dimensional inverse synthetic aperture radar imaging,the coupling scattering mechanisms between different targets and metal pylon are analyzed.Methods for coupling scattering suppression are proposed.Numerical calculation and simulation results are presented to demonstrate the usefulness of the proposed techniques.