机载前视阵列SAR运动补偿研究

摘要

Combined with Frequency-Modulated Continuous-Wave (FMCW) technology, airborne forward-looking Synthetic Aperture Radar (SAR) with linear array antennas can obtain the images in front of an aircraft, while having the advantages of FMCW radar such as small size and lightweight. Moreover, it is suitable for installation on platforms such as helicopters and small unmanned aerial vehicles. In practice, motion compensation for forward-looking SAR with linear array antennas is one of the key problems to obtaining the images in front of aircraft. This paper uses linear array antennas to analyses the influence of motion error in aircraft on an echo model based on the geometry of forward looking SAR, with linear array antennas, and proposes a motion compensation scheme. Moreover, the compensation scheme is applied to an improved Frequency Scaling Algorithm (FSA) for FMCW forward looking SAR with linear array antennas. Finally, the compensation scheme is verified using simulations.%　　结合调频连续波(FMCW)技术的机载前视阵列合成孔径雷达(SAR)既能够获取飞机前下方区域图像，又具有FMCW体制雷达体积小、重量轻的优势，易于安装在直升机等轻小型平台。前视阵列SAR的运动补偿是获得前视图像信息的关键问题之一。该文根据前视阵列SAR的几何模型，分析了载机平台运动误差对回波的影响，研究了相应的运动补偿方法。在此基础上，将补偿方法嵌入到一种基于FMCW的前视阵列SAR的改进频率变标算法(FSA)中。最后通过仿真实验验证了该补偿方法的有效性。