MPPE-CME: Multipolarimetric Phase Estimation for Distributed Scatterers With Improved Coherence Matrix Estimation

With the launch of a number of multipolarimetric synthetic aperture radar (SAR) satellites, many multipolarimetric phase estimation algorithms have been introduced to reduce the decorrelation of distributed scatterers (DSs). They typically perform the traditional phase estimation on complex coherence matrix. Thus, the primary focus lies in accurately estimating the complex coherence matrix to achieve precise phase estimation. In this article, we propose a multipolarimetric phase estimation approach with improved coherence matrix estimation, termed MPPE-CME. It includes two major steps. The first step is to select the polarimetric interferometric pairs using our proposed selection algorithm, which is adaptive and without setting any empirical parameters. In the second step, based on the selected polarimetric interferograms, we develop a dominant scattering mechanism (SM) extraction algorithm to estimate the complex coherence matrix with enhanced accuracy. The simulated experiment validates the effectiveness of the proposed polarimetric interferometric pair selection and dominant SM extraction algorithms. The real data experiment conducted at the Chengdu Tianfu International Airport demonstrates that MPPE-CME outperforms other multipolarimetric phase estimation algorithms with significantly reduced reconstructed phase noise, increased measurement point (MP) density, and improved deformation accuracy.