Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Selective Weighting of Undecimated Wavelet Coefficients for Noise Reduction in SAR Interferograms | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2008 Article ID 378092 8 pages doi 2008 378092 Research Article Selective Weighting of Undecimated Wavelet Coefficients for Noise Reduction in SAR Interferograms Vidhyasaharan Sethu 1 Eliathamby Ambikairajah 1 and LinlinGe2 1 School of Electrical Engineering and Telecommunications The University of New South Wales Sydney NSW 2052 Australia 2 School of Surveying and Spatial Information Systems The University of New South Wales Sydney NSW 2052 Australia Correspondence should be addressed to Vidhyasaharan Sethu vidhyasaharan@ Received 2 January 2007 Revised 10 October 2007 Accepted 13 February 2008 Recommended by A. Enis Cetin This paper describes a technique for noise reduction in synthetic aperture radar interferometry. The noisy interferogram is decomposed using undecimated wavelet transform and the coefficients are weighted. A novel method for computing the weights for each subband based on an estimate of the relative noise content in them is presented with a median filter used as the noise estimator. The proposed technique is not optimised for any specific signal or noise models. Results show that this technique provides an improvement of around 15 over the conventional boxcar filter in terms of estimated height error of a digital elevation model constructed from the filtered interferogram. Copyright 2008 Vidhyasaharan Sethu et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION Synthetic aperture radar interferometry InSAR is an established technique for the extraction of height information by using SAR remote sensing 1 . It uses two high-resolution complex SAR images of the same scene to generate an interferogram. The phase information contained in this interferogram is extracted to
