Fig. 6 shows change detection maps derived from 2010/11 to
2011/04 pairs for each polarimetric parameter. The reference image in
Fig. 6(a) is derived from the damaged area maps (http://danso.env.
nagoya-u.ac.jp/20110311/map/) produced by the Geospatial Information
Authority of Japan (GSI). Fig. 6(b) and (c) indicates that changes
(post–pre) in the conventional single-channel backscatter measurement,
for either HH- or VV-polarization, cannot provide useful information
about damage caused by earthquakes or tsunamis. However,
damaged areas can be identified from several different polarimetric
parameters