Topographic correction of polarimetric synthetic aperture radar and its application in snow and ice mapping

Fu Sitao; Li Zhen; Tian Bangsen

doi:10.11834/jig.20140119

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Topographic correction of polarimetric synthetic aperture radar and its application in snow and ice mapping
Vol. 19, Issue 1, Pages: 150-157(2014)
Published：2014
DOI： 10.11834/jig.20140119
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DOI：

Fu Sitao, Li Zhen, Tian Bangsen. Topographic correction of polarimetric synthetic aperture radar and its application in snow and ice mapping[J]. Journal of Image and Graphics, 2014, 19(1): 150-157. DOI： 10.11834/jig.20140119.

摘要

针对合成孔径雷达（SAR）影像由于地形起伏引起的图像畸变问题，提出了基于相干矩阵的全极化SAR影像地形纠正算法，并运用于雪冰制图。该方法首先采用距离多普勒模型建立SAR成像几何模型；然后利用全极化Cloude特征分解方法对全极化SAR图像进行融合，将融合后的SAR图像与模拟图像进行配准提高SAR影像几何定位精度；最后利用投影面积归一化和极化方位角移动补偿技术对地形引起的辐射畸变进行纠正。采用中国长江源区南部唐古拉山中段冬克玛底冰川区域的C波段Radarsat-2全极化SAR数据进行验证，配准模拟SAR和原始SAR影像的控制点方位向和距离向的均方根误差（RMSE）分别为7.765像素和14.586像素；经过地形纠正后的地物分类精度达80%以上。实验结果表明：1）该方法能够有效消除SAR影像中几何和辐射畸变的影响；2）地形纠正后的SAR数据在雪冰制图中具有可行性。

Abstract

To eliminate the influence of image distortions due to the topographic relief. A novel method for the topographic correction of Polarimetric SAR (PolSAR) based on the coherence matrix has been put forward. First

the imaging geometry is reconstructed firstly based on the Range-Doppler mode. Then

the fused SAR image is obtained Cloude decomposition

which is used to match the simulated image to improve the geometric correction accuracy. Finally

the topographic correction for PolSAR is completed by the projection area normalization method and polarization azimuth shift compensation. To test the proposed method

a Radarsat-2 PolSAR image in C-band of the in Donkemadi district in China has been corrected and then applied to map the glacier. The RMSE of azimuth and range direction of register is 7.765 and 14.586 pixels and the accuracy of classification after topographic correction is more than 80%

Which proves: 1) The proposal method is able to remove geometric and radiometric distortion;2) the usage of polarization SAR in C-band in glacier mapping is feasible after the topographic correction.