修正二面角散射模型的改进四分量分解

Improved four-component decomposition with a modified double-bounce scattering model

提出了一种面向极化合成孔径雷达数据的改进四分量分解方法.针对极化分解中体散射过高估计问题,改进极化分解使用分布二面角散射模型替代四分量分解原相干偶次散射模型,并引入归一化圆相关系数以实现分解.将改进极化分解运用到奥伯法芬霍芬(Oberpfaffenhofen)地区的实验合成孔径雷达(Experimental Syn-thetic Aperture Radar,E-SAR)的全极化机载L波段数据和北京地区的先进陆地观测卫星L波段相控阵合成孔径雷达(the Phased Array L-band SAR sensor ofAdvanced Land Observing Satellite,ALOS PALSAR)的全极化星载数据,通过负功率像素、地物散射分量的对比,以及分解结果和光学图像的比对三个方面说明了改进极化分解的有效性.改进极化分解能够有效降低体散射分量,减少负功率像素个数,以及正确获得45°建筑的散射机制.

An improved four-component decomposition scheme for analyzing polari metric synthetic aperture radar（POLSAR）data is proposed in this paper. To solve the problem of volume scattering overestimation, the improved decomposition utili- zes the new double-bounce model of distributed dielectric dihedral corner reflectors instead of the original one adopted by the Yamaguchi four component decomposi tion. To be performed, the improved decomposition introduces normalize circular-pol correlation coefficients in the decomposition process. An airborne L band qua＆pol data acquired by DLR E-SAR sensor over Oberpfaffenhoffen area in German and a spaeeborne L band quad-pol data over Beijing acquired by the Phased Array L-band SAR sensor of Advanced Land Observing Satellite （ALOS PALSAR ）are applied to the improved decomposition scheme. Three comparisons have been made to demon strate the effectiveness of the improved decomposition , including the number ofneTgative power pixels,the magnitude of each scattering mechanism, and perform ance between the decomposition results and optical image. The improved decomposi tion can reduce the pixels with negative powers and obtain correct scattering mecha nisms of non-reflection structures not paralleled to the flight path.