摘要
多旋翼无人机载合成孔径雷达(SAR)相较于传统的固定翼机载SAR具有轻便易携带、使用方便等优点,然而它也更易受气流扰动影响,误差空变性更强,这对运动补偿提出了很高的要求。本文建立了调频连续波体制下加入视线向误差后的SAR信号模型,推导了调频连续波体制下正侧视SAR的两步运动补偿法,指出了该方法以及其改进方法运用在多旋翼无人机载SAR数据处理时的不足。为克服已有方法的缺点,本文提出了“逐距离单元补偿法”。该方法针对每一距离单元均计算出对应的补偿函数,每次补偿后仅输出对应距离单元的数据。相较于其他补偿方法,该方法更精确地补偿了斜距和视线向速度的空变误差,且减少了剩余误差对各成像步骤的影响。本文最后通过仿真验证了所提方法的有效性。
Compared with the traditional fixed-wing-aircraft-borne synthetic aperture radar(SAR),multi-rotor UAV SAR is more convenient to carry and operate. However,it is also more susceptible to air disturbance and its motion error has more serious spatial variability,which puts forward high requirements for motion compensation. In this paper,the signal model of frequency-modulated-continuous-wave(FMCW)SAR with line-of-sight(LOS)motion error was established,and the two-step motion compensation method of FMCW SAR was derived,then the shortcomings of this algorithm and its improved algorithm in the application of multi-rotor UAV SAR were pointed out. In order to make the compensation of SAR based on the inertial measurement unit(IMU)data more accurate,this paper proposed a "range-cell-by-cell compensation method". The method calculates the corresponding compensation function for each range cell,and only outputs the data of the corresponding range cell after each compensation. Compared with other compensation methods,this method can compensate the space-variant slant range error and velocity error more accurately and reduce the influence of residual error on each imaging step. Finally,the effectiveness of the algorithm was verified by simulation.
作者
黎涛
付耀文
张健丰
张文鹏
杨威
LI Tao;FU Yaowen;ZHANG Jianfeng;ZHANG Wenpeng;YANG Wei(Dept.of Intelligence Perception,College of Electronic Science,National University of Defense Technology,Changsha,Hunan 410003,China)
出处
《信号处理》
CSCD
北大核心
2022年第3期491-501,共11页
Journal of Signal Processing
基金
国家自然科学基金(61871384)。
关键词
合成孔径雷达
运动补偿
多旋翼无人机
synthetic aperture radar(SAR)
motion compensation
multi-rotor UAV
