Improved ESPO Method Based on Spatial Variation of Scattering Mechanisms for MT-PolInSAR

The existing exhaustive search polarimetric optimization (ESPO) method exploiting polarimetric diversity has been widely used to improve the phase quality in polarimetric interferometric synthetic aperture radar (PolInSAR). However, the optimization ceiling of the ESPO method based on the coherence metric is largely restricted by the variation of scattering mechanisms in the spatial domain, especially for high-resolution SAR data. To this end, this letter proposes an improved ESPO (ImESPO) method that considers the changes in the scattering mechanisms in local windows and applies it to the time-series phase optimization framework. Both simulated and real experiments demonstrated the effectiveness of the proposed method, which shows that the changes in the scattering mechanisms are more serious in the large window or for high-resolution SAR data. In addition, the effects of the filtering window size and the number of interferograms on optimization were also analyzed in detail.

Automated summary

This study proposes an improved ESPO (ImESPO) method by considering the changes in scattering mechanisms in local windows and applying it to the time-series phase optimization framework, thus further optimizing the phase quality in polarimetric interferometric synthetic aperture radar (PolInSAR). Both simulated and real experiments demonstrate the effectiveness of the proposed method, showing that the changes in scattering mechanisms are more severe in larger windows or for high-resolution SAR data. Moreover, the effects of filtering window size and the number of interferograms on optimization are also analyzed in detail.