利用点目标进行SAR辐射定标的方法研究

SAR辐射定标是一项关联图像像素值和地物后向散射系数的重要工作。由于角反射器具有稳定、大的散射截面积和在较宽的角度范围内散射截面积变化较小,因而成为重要的点目标定标器。研究利用已知散射截面积的三面体角反射器来计算不同地物的后向散射系数、系统定标常数和系统总的传递函数的方法,并通过大量实测SAR数据进行了定标实验。理论分析和实验结果表明,利用点目标进行SAR辐射定标具有简单、实用、精度较高的优点。

Research on Approach of SAR Radiometric Calibration Using Point Target

Radiometric calibration of synthetic aperture radar (SAR) is an important work to relate pixel values and the backscattering coefficient of ground targets.The trihedral corner reflector with high stability,large RCS and little change within a wide angle range is one of point target calibrations.Airborne SAR data including many trihedral corner reflectors is utilized to compute backscattering coefficient of different targets,calibration constant and transfer function of system.Calibration experiments were carried out.Theoretic analysis and experimental results show that radiometric calibration using point target is simple,practicable,and relatively accurate.