Beijing 2008 
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B7. Beijing 2008 
1-like surface 
(a) Original GERM approach 
(b) Improved GERM approach 
Figure 3. The improved cluster based GERM approach (b) shows more consistent results in the mosaic comparing to the original 
GERM approach (a). Note that right side of ASTER mosaic (separated by red dash line) has same acquisition date to 
MODIS target date (on April 10, 2006), thus results from (a) and (b) are almost identical for the right side. The cluster 
based GERM approach shows better result when ASTER acquisition date (left side ASTER scene acquired on January 27, 
2006) is different from MODIS target date (April 10, 2006). The lower reflectance such as river in (a) seems too high 
from original GERM approach. 
(a) From ASTER Digital Number Mosaic 
(b) From Normalized Surface Reflectance 
Figure 4. Maximum likelihood classification results from original DN images (a) and the normalized surface reflectance (b). The 
classification based on the normalized surface reflectance image shows more consistent results across different ASTER 
scenes. (green=forest; yellow=crops/grass; red=urban/built-up; blue=water)