柔性基线抖动对机载干涉SAR性能影响分析

Performance Analysis for Airborne Interferometric SAR Affected by Flexible Baseline Oscillation

机载干涉SAR平台在飞行过程中通常会受气流、机械振动等因素的影响,造成柔性基线抖动,从而严重影响干涉SAR系统的性能。该文针对柔性基线机载干涉SAR系统中的基线抖动问题,首先推导了基线抖动下的斜距误差模型,然后从1次、2次和一般斜距误差建立了SAR复图像信号模型和双通道相关系数模型,并理论分析了基线抖动对SAR成像和干涉性能的影响。最后通过回波仿真实验验证了理论分析的正确性。

The airborne interferometric SAR platform suffers from instability factors, such as air turbulence and mechanical vibrations during flight. Such factors cause the oscillation of the flexible baseline, which leads to significant degradation of the performance of the interferometric SAR system. This study is concerned with the baseline oscillation. First, the error of the slant range model under baseline oscillation conditions is formulated. Then, the SAR complex image signal and dual-channel correlation coefficient are modeled based on the first-order, second-order, and generic slant range error. Subsequently, the impact of the baseline oscillation on the imaging and interferometric performance of the SAR system is analyzed. Finally, simulations of the echo data are used to validate the theoretical analysis of the baseline oscillation in the airborne interferometric SAR.