Polarimetric Feature Investigation of Scattering from Manmade Structures for Improving Change Detection of Flood-affected Urban Area

Change detection using time-series polarimetric synthetic aperture radar (PolSAR) is an effective method for recognizing disaster-affected urban area [1]. However, the accuracy of the conventional method may not be enough if exterior of building is not damaged but road surrounding the building is covered by ruble and/or sediment of the flooded water after flood event, as in Figure 1 (a). For such case, primary scattering (double bounce scattering) from the building area is not changed but secondary/tertiary scattering (surface scattering/volume scattering) from other parts may be changed. It is not easy to detect the change of the secondary/tertiary scattering, since the power of such scattering is generally not large. So, we now take notice of the change detection concerning scattering with small power, in addition to primary scattering with large power.