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.根据FMCW体制下前视阵列SAR的几何模型分析其回波信号模型以及其由载机运动引起的多普勒频移,研究相应的补偿方案,给出一种基于FMCW的前视阵列SAR的改进频率变标(FS)算法.通过仿真验证了算法的有效性.
Airborne forward-looking synthetic aperture radar(SAR) with linear array antennas based on frequency-modulated continuous-wave(FMCW) technology can obtain the image in front of the aircraft and it has the advantages of FMCW radar such as small size and lightweight.Moreover,it is suitable for installation on platforms like helicopter and small unmanned aerial vehicle.We analyze the echo model based on geometry of forward looking SAR with linear array antennas based on FMCW and the Doppler frequency shift due to the movement of the aircraft,propose a corresponding compensation scheme,and then present an improved frequency scaling algorithm based on FMCW forward looking SAR with linear array antennas.Finally,the algorithm is verified with the simulation.