L2-norm deformation phase unwrapping in mining area driven by matrix pencil model

DUAN Lei; HUA Xia; ZENG Xiangkai; CHEN Liping; ZHANG Haonan; SONG Rui; XIAO Han

doi:10.13347/j.cnki.mkaq.20240803

Abstract：To address the limitations of traditional phase unwrapping(PU)approaches in differential interferometric synthetic aper-ture radar(DInSAR)technology which performs poorly in unwrapping low-coherence deformation interferograms in mining areas,an L2-norm PU approach driven by the matrix pencil model is proposed.Using the improved matrix pencil local frequency estimator,the wrapped phase gradients of deformation interferograms are accurately extracted in four directions:horizontal,vertical,and the two diagonals.These gradients are then integrated with the four-direction weighted least squares PU algorithm,utilizing the Gauss-Seidel iteration method to compute the unwrapped deformation phase of the mining surface.It not only preserves the advantages of high unwrapping efficiency and smooth phase surfaces but also effectively mitigates noise interference during the PU process.Exper-imental results based on mining subsidence simulation data demonstrate that the proposed approach ensures high continuity in the unwrapped phase,minimizes residuals and unwrapping errors,and improves PU accuracy by approximately 73.5%,46.2%,and 74.1%,respectively,compared to the minimum-cost flow,statistical-cost network-flow,and traditional four-direction weighted least squares PU methods.Additionally,three coal mining collapse sites in Yongcheng Mining Area of Henan Province were selected as experimental subjects to carry out tests.Experimental results based on Sentinel-1A data demonstrate that the proposed approach provides more accurate,complete,and smooth unwrapped deformation phase compared to commonly used PU algorithms in engin-eering applications,such as network-flow and max-flow/min-cut methods.This new approach significantly enhances the accuracy and noise resistance of the L2-norm unwrapping model.