DOI number:10.1109/TGRS.2020.2991837
Journal:IEEE Transactions on Geoscience and Remote Sensing
Key Words:Complex coherence estimation, equivalent number of looks (ENL), nonlocal means (NLM), nonlocal reduced bias (NLRB) estimator, polarimetric synthetic aperture interferometry (PolInSAR), shape-adaptive (SA) patches matching
Abstract:The traditional nonlocal estimations have been demonstrated to be effective and widely used in polarimetric synthetic aperture radar interferometry (PolInSAR) data. However, there still exist some problems about two key steps: 1) in the homogeneous pixels selection step, the regular square (RS) patches matching strategy shows the limited performance in textured area and 2) in the central pixel value estimation from the selected pixels, the well-known Lee estimator, which only uses the intensity statistic, tends to be unstable. To overcome these restrictions, we put forward two robust strategies and then propose an improved PolInSAR complex coherence nonlocal estimation: 1) the shape-adaptive (SA) patch is utilized for flexibly matching the similar pixels in a large search window, which is constructed by combining the likelihood ratio test (LRT) and the region growing (RG) algorithm and 2) the trace-moment-based nonlocal reduced bias (TMB-NLRB) estimator is employed, which considers the interchannel correlations and evaluates more accurately the homogeneity level between the selected pixels. The denoising effect of both strategies is quantitatively analyzed on the simulated data set, and the proposed algorithm is compared with classical estimation algorithms on a TerraSAR-X/TanDEM-X PolInSAR data set. These experimental results show that the proposed method provides better performance in speckle reduction, detail preservation, and complex coherence estimation.
Co-author:Luo Xingjun, Fu Haiqiang, Zhu Jianjun
Indexed by:Journal paper
Correspondence Author:Wang Changcheng
Discipline:Engineering
Document Type:J
Volume:59
Issue:1
Page Number:260-272
Translation or Not:no
Date of Publication:2020-05-19
Included Journals:SCI
Links to published journals:https://ieeexplore-ieee-org-s.vpn.whu.edu.cn/document/9096581
Date of Publication:2020-05-19