309 
Fig.8 Residential area 
Fig.7 Vegetation 
4.4 Residential Area 
In residential area, there are many dihedral angel and 
polyhedral angle reflectors formed by walls of the building and 
dams with the ground, so they make the radar beam reflect 
times without number, so as to enhance the echo. Therefore, the 
residential area is obvious in the SAR image, and has clear 
texture. 
5. CONCLUSIONS 
Through this research, it obviously shows that the high 
resolution airborne SAR image is capable of updating 
topographic map elements. By making use of abundant texture 
feature, various map elements could be distinguish in the SAR 
image, and changes also could be easily find in the map. SAR 
image could be the well complementary to the optical image, 
specially for the place where could not have optical image. In a 
word, it is feasible to use high resolution airborne SAR image 
in updating topographic map. 
REFERENCES 
Kang.T.J, Wu.W.B, Yu.H, 2006 Technique study on updating 
large scale topographic map using Remote sensing image, 
http ://www.paper. edu.cn 
Rignot.E, Kwok.R,2003 Extraction of texture features in SAR 
images: statistical model and sensitivity. International 
Geoscience and Remote Sensing Symposium. 
Shu.N, 2003 Principles of Microwave Remote Sensing, pp. 
55-56 
Zhao. Z, Zhang.J.X, Huang.GM, 2004 Experiment research 
of high resolution AIRSAR data. Science of Surveying and 
Mapping, vol.28 No.6, pp. 34-37 
ACKNOWLEDGEMENT 
This work was supported by State Bureau of Surveying and 
Mapping key laboratory of Geographic Information 
Engineering Foundation of Researches, Grant B2620