2.2 Image pre-processing
Landsat 7 Enhanced ThematicMapper Plus (ETM+) image
(Oct 13, 2002) and Landsat 5 TM images (Oct 26, 1988; Oct 23,
1991; Oct 4, 1996) were used in this research. The data
acquisition date has a highly clear atmospheric condition. All
images bands 1-5 and 7 have a spatial resolution of 30m, and
the thermal infrared band (band6) has a spatial resolution of
120m for Landsat 5 TM imagesand 60m for Landsat 7 ETM+
images. The Landsat image were further rectified to a common
Universal Transverse Mercator coordinate system based on
1:24,000 scale topographic maps, and were resampled using the
nearest neighbor algorithm with a pixel size of 30 by 30 m for
all bands including the thermal band. The resultant RMSE was
found to be less than 0.5 pixels.