视频合成孔径雷达振动误差分析及补偿方案研究

视频合成孔径雷达(Video Synthetic Aperture Radar, ViSAR)具有成像帧速快、分辨率高等优点,对近距运动目标的精细侦查和定位有迫切应用需求.相比微波段SAR成像系统,ViSAR载波波长短,平台的微小振动会引起回波信号相位的显著变化,常常导致图像无法聚焦,使得ViSAR在实际应用中受到限制,因此有必要开展ViSAR运动误差分析及其补偿技术的研究.该文分析结果表明,载机平台在飞行方向的振动和在斜距方向的低频振动对成像结果影响较小,而在斜距方向的高频振动对成像结果影响较大,要求补偿精度较高.鉴于ViSAR运动补偿的特殊性,该文提出一种运动补偿方案,可以满足ViSAR成像中的补偿精度要求,最后通过ViSAR成像仿真实验初步验证了理论分析的正确性和运动补偿方案的有效性. 

Vibration Error Analysis and Motion Compensation of Video Synthetic Aperture Radar

Video Synthetic Aperture Radar (ViSAR) system offers high imaging frame rate, and high resolution, and it is consequently used to investigate and locate near-moving targets. Compared with microwave SAR, the practical application of ViSAR is restricted by motion compensation caused by short wavelength. Even slight platform vibrations cause significant variations in the phase of echo signal.Thus, it is imperative to analyze the motion compensation and the error of ViSAR. In this study, the results show that imaging is affected less in the direction of flight direction and by low vibration in the direction of the slant range. In contrast, high-frequency vibration in the direction of the slant range requires higher compensation accuracy. Given the particularity of ViSAR's motion compensation, a compensation scheme is designed to achieve high compensation precision .The effectiveness of the scheme is verified by ViSAR imaging simulation experiments.