A Fast Offset Estimation Approach for InSAR Image Subpixel Registration

	A Fast Offset Estimation Approach for InSAR Image Subpixel Registration
	Li, Dong; Zhang, Yunhua
刊名	IEEE GEOSCIENCE AND REMOTE SENSING LETTERS
	2012
卷号	9 期号:2 页码:267-271
关键词	Fast offset estimation interferometric SAR (InSAR) subpixel image registration synthetic aperture radar (SAR)
ISSN号	1545-598X
通讯作者	Li, D (reprint author), Chinese Acad Sci, Ctr Space Sci & Appl Res, Key Lab Microwave Remote Sensing, Beijing 100190, Peoples R China.
中文摘要	A fast offset estimation approach for interferometric synthetic aperture radar (InSAR) image pair subpixel registration is proposed for cases of relatively gentle topography and/or short baseline. A coarse-to-fine registration strategy is taken. The pixel-level offset is estimated in the coarse registration step by a fast feature-based estimation, which uses the speeded up robust feature operator and fast least trimmed squares (Fast-LTS) estimator to accelerate the feature extraction and parameter estimation. A fine registration is performed subsequently. The conventional normalized cross-correlation algorithm (NCCA) searches for the optimal subpixel offset by oversampling either the coarse cross correlation or the InSAR image patch pair. The offset estimation accuracy is restricted by the oversampling rate, and the computational burden is heavy when high accuracy is demanded. In this letter, we transform the oversampling and correlation searching process of NCCA into a nonlinear optimization problem, which takes the maximization of the coherent cross correlation as the objective function; by solving it, the subpixel offset can be fast and exactly obtained without any image oversampling. The final registration parameters are inverted by Fast-LTS fitting of a series of subpixel tie point correspondences which can be constructed after applying the approach to several image patch pairs. RadarSat-2 data are used to test the approach, and the results show that it performs very well not only on the speed but also on the accuracy.
英文摘要	A fast offset estimation approach for interferometric synthetic aperture radar (InSAR) image pair subpixel registration is proposed for cases of relatively gentle topography and/or short baseline. A coarse-to-fine registration strategy is taken. The pixel-level offset is estimated in the coarse registration step by a fast feature-based estimation, which uses the speeded up robust feature operator and fast least trimmed squares (Fast-LTS) estimator to accelerate the feature extraction and parameter estimation. A fine registration is performed subsequently. The conventional normalized cross-correlation algorithm (NCCA) searches for the optimal subpixel offset by oversampling either the coarse cross correlation or the InSAR image patch pair. The offset estimation accuracy is restricted by the oversampling rate, and the computational burden is heavy when high accuracy is demanded. In this letter, we transform the oversampling and correlation searching process of NCCA into a nonlinear optimization problem, which takes the maximization of the coherent cross correlation as the objective function; by solving it, the subpixel offset can be fast and exactly obtained without any image oversampling. The final registration parameters are inverted by Fast-LTS fitting of a series of subpixel tie point correspondences which can be constructed after applying the approach to several image patch pairs. RadarSat-2 data are used to test the approach, and the results show that it performs very well not only on the speed but also on the accuracy.
学科主题	微波遥感
收录类别	SCI ; EI
语种	英语
公开日期	2014-12-15
内容类型	期刊论文
源URL	[http://ir.nssc.ac.cn/handle/122/3454]
专题	国家空间科学中心_微波遥感部
推荐引用方式 GB/T 7714	Li, Dong,Zhang, Yunhua. A Fast Offset Estimation Approach for InSAR Image Subpixel Registration[J]. IEEE GEOSCIENCE AND REMOTE SENSING LETTERS,2012,9(2):267-271.
APA	Li, Dong,&Zhang, Yunhua.(2012).A Fast Offset Estimation Approach for InSAR Image Subpixel Registration.IEEE GEOSCIENCE AND REMOTE SENSING LETTERS,9(2),267-271.
MLA	Li, Dong,et al."A Fast Offset Estimation Approach for InSAR Image Subpixel Registration".IEEE GEOSCIENCE AND REMOTE SENSING LETTERS 9.2(2012):267-271.