基于ISAR成像的目标大角度RCS外推

传统逆合成孔径雷达(ISAR)转台成像算法对目标进行成像后只能外推小角度区域雷达散射截面(RCS)。针对这一问题,建立了大转角转台成像系统,提出了一种基于近场微波成像的RCS外推算法,分析了近场大转角转动带来的越距离单元徙动问题。通过将距离与方位域解耦,并对方位方向进行圆周卷积运算,得到高质量的目标成像,进而可以外推目标360度方位的RCS,并与传统ISAR小角度成像算法进行比对。仿真结果表明,外推算法不仅可以对目标进行成像,诊断目标的强散射点位置,还可以用来做远区RCS大角度外推,并结合成像结果分析目标散射机理。

RCS Computation Technique Based on ISAR Imaging for Large Angular Rotation Problem

In this paper,a radar cross section(RCS) extrapolation method was proposed based on inverse synthetic aperture radar(ISAR) imaging system with large angular rotation.It can solve the problem that the ISAR system can not deal with the small angle rotation problem to acquire the RCS.The range cell migration problem caused by large angle rotation was also considered.The proposed system was accomplished by decoupling the green function to range direction and azimuth direction.In azimuth direction,the convolution method was used to obtain the accurate images rapidly.Then,the images were used for RCS extrapolation over 360 degree.The proposed method is testified by simulation results.The results show that the proposed method can be used to acquire high resolution image which can be used for high quality RCS extrapolation.