机载高分辨力SAR实时运动补偿的实现

The implement of real-time motion compensation for high resolution airborne SAR

本文详细地分析了载机运动误差与回波相位的关系,提出了基于G4DSP信号处理板的机载SAR实时运动补偿方法,该方法利用G4DSP的四个CPU构成流水线处理器,采用子孔径方法分段提取回波的多普勒调频斜率,然后利用调频斜率的变化计算载机的运动误差,通过相位误差函数与方位数据的时域相乘补偿运动误差。实时信号处理机的实验表明,本文方法能实时和有效的实现机载SAR运动补偿,获得满意的成像质量。

This paper analyzes the relation of airplane motion error and target echoes phase in detail, and proposes the real time motion compensation implemental method for airborne SAR based upon the G4DSP board. By constituting the pipelining processor using the four CPU on the G4DSP board, this method makes use of sub-aperture technique to estimate the sub-aperture＇ s Doppler rate, then calculates the airplane motion error by the Doppler rate variation, and compensates motion error by multiplying the phase error function and azimuth data in time domain. The experiment results of the real-time signal processor show that this method can effectively compensate the airplane motion error in real-time, and improve the SAR image quality.