Urban damage mapping using scattering mechanism investigation technique for fully polarimetric SAR data

Mapping of the urban damage levels with synthetic aperture radar (SAR) is still challenging. Fully polarimetric SAR (PolSAR) has the potential to identify the type of scattering mechanism changes induced by urban damage. In radar polarimetry, dominant double-bounce scattering mechanism in urban areas is primarily induced by the ground-wall structures. Thereby, within an urban patch, the reduction of the dominant double-bounce scattering mechanism reflects the urban damage level in terms of destroyed ground-wall structures, which is the basis of this study. Based on our previous study, the proposed polarimetric index is further investigated. A rapid urban damage mapping technique including mainly two steps of urban area extraction and damage level index estimation is proposed. The 3.11 East Japan Earthquake and Tsunami is adopted as the study case using multi-temporal ALOS/PALSAR PolSAR data. Experimental studies demonstrate that the estimated damage levels are closely consistent to the ground-truth.