An algorithm of filtering InSAR interferogram based on the combination of wavelet transform and sigma filter

Abstract

In order to enhance the quality in filtering InSAR interferograms, this paper proposes and constructs a Wavelet-Sigma filter (WSF) in view of the respective merits of wavelet transform and Sigma filter. The WSF and its computer program are developed to remove interferogram noise. To validate the proposed filter, the localized area around Bam of Iran is selected as the testing site an ASAR C-band interferogram is utilized as the source data for filtering. Several indicators, including visualization effect, standard deviation of phase derivatives and number of residues, are taken into account to assess the effectiveness of this filter. The results show that WSF has some prominent advantages in terms of denoising and edge protection, if compared with two typical methods presented previously, i.e., wavelet soft-threshold filter and Sigma filter. © 2013. The authors.