基于误差控制的SAR投影失真快速校正算法

A Fast Projection Distortion Calibration Correction Method of SAR Image Based on Error Control

随着合成孔径雷达(SAR)技术的发展和广泛应用,为了更准确反映场景信息,几何校正成为SAR图像处理过程中的重要内容。文中根据机载SAR成像机理,分析了引起机载SAR图像几何投影失真的原因,并估算出其失真量,针对传统的非线性校正方法,提出了一种快速高效的基于误差控制的动态分段线性校正算法。该算法在保证SAR图像校正质量的前提下,通过控制SAR图像校正误差,用线性处理取代了非线性逐点运算,使得校正算法的计算复杂度大大降低。文中还从理论上推导出最佳的分段校正长度计算方法,可校正过程中动态调整分段长度,保证校正质量和运算效率。最后通过仿真试验验证了该文法的有效性和实用性。

With the development and wide application of SAR technology,the geometric correction is an important content of the SAR image processing to present the true information of the scene.Based on the imaging principle of air-borne SAR,this paper analyzes the main reason which causes the geometry projection calibration distortion in air-borne SAR image,and estimates the distortion.Compared with the traditional nonlinear correction method,this paper suggests a fast and efficient geometric correction method by dynamic segment which is based on the error control.In the scope of the SAR image correction quality and the control of the SAR image correction error,we substitute the nonlinear operation with linear processing,which results in the computation complexity of correction be reduced greatly.This paper also derives a calculation method of the best partition length,and adjusts the partition length adaptively in the process of geometric correction.It guarantees the correction quality and the operation efficiency.Finally,simulation verified the validity and practicability of the algorithm.