基于DPCA的机载SAR系统运动误差及其补偿

Calibration of Movement Error of Airborne SAR System Based on DPCA Technique

基于相位中心偏置天线(DPCA)技术的机载SAR系统在实际运用中普遍存在着因雷达平台运动不稳定导致DPCA约束条件不满足的问题,这在很大程度上影响了机载SAR系统的杂波抑制性能。针对这个问题,该文以双天线机载SAR系统为模型,通过对DPCA的对消原理和运动误差的分析,结合插值理论,对载机匀加速运动状态下造成的运动误差提出了一种基于三次样条函数的运动补偿算法。通过计算机仿真,验证了该算法的有效性,且算法易于工程实现。

A main problem of airborne SAR based on DPCA technique is that the movement instability of a radar platform causes the dissatisfying of DPCA condition. This problem conduces the performance decline of clutter suppression of airborne SAR system. In this paper, based on the model of dual-antenna airborne SAR system, the cancellation theory of DPCA and the movement error are analyzed. On the ground of interpolation theory, a new calibration algorithm of movement error based on cubic spline function is provided for this problem when the radar platform moves in the state of uniform acceleration. By the simulation results, the validity of this algorithm is demonstrated. This method can be easily realized in engineering practice.