前斜视SAR成像目标高精度模拟技术

High Precision Simulation Technique of Squinted SAR Imaging Target

前斜视合成孔径雷达(SAR)成像的距离-方位存在强耦合,目标径向运动信息的模拟精度不仅影响雷达的距离像分辨性能,同时影响方位像分辨性能。通过对距离调制分辨率与SAR成像结果的理论分析,提出了一种频域插值升采样调制的SAR成像回波模拟方法,通过提高采样率以减小距离徙动引起的幅度误差,同时采用GPU并行处理,提高回波模拟的实时性。结果表明:所提出的方法能够达到0.1 m的距离延时模拟精度,并对256×256点场景回波的运算周期小于10μs,可适用于前斜视SAR目标高精度模拟。

There is strong coupling between the range and azimuth of squint synthetic aperture radar(SAR)imaging,the simulation accuracy of the target radial motion affects both the range image resolution of the radar and the azimuth image resolution.By theoretically analyzing the range modulation resolution and SAR imaging results,a simulation method of squint SAR echo signals by upsampling modulation of frequency domain interpolation is proposed,which reduces the magnitude error resulted from range migration by increasing the sampling rate.Meanwhile,GPU parallel computation is employed to improve the real-time performance of SAR echo signals.The results show that the proposed method can achieve a distance delay simulation accuracy of 0.1 m,and the operation period of the echo from a scene of 256×256 is about 10μs,which is suitable for high-precision simulation of large squint SAR targets.