3. METHOD
3.1. Detecting flooded areas
Water bodies show low sigma naught due to the effects of
mirror reflection. To detect water bodies, threshold value was
determined focusing on the local minimum value in the histogram
derived using pre-event TerraSAR-X data. After removing
the noise by a majority filter, water bodies located in
high location is excluded using ASTER GDEM assuming that
is regardless of tsunami. Finally, the boundary of the flooded
areas is estimated by drawing the envelope of water bodies as