3.3.3. Determination of the region of collapsed buildings
In this section, under the assumption that post-seismic elevations
of the collapsed buildings will be lower than the pre-seismic
elevations, the region of collapsed buildings is detected using the
difference DEMs created from the pre- and post-seismic stereo
images. Turker and Cetinkaya (2005) considered a similar method
using pre- and post-seismic stereo aerial photographs. The spatial
resolution of the pre-seismic aerial photographs was 0.22 m, and
that of the post-seismic photographs was 0.49 m. However, in
our study, the spatial resolution of both the pre- and post-seismic
stereo IKONOS images is 1.0 m, which is much coarser than the resolution
of the aerial photographs. In addition, owing to errors
inherent to the sensor model of the satellite, it is challenging to improve
the accuracy of ground point determination when using