Figure 4a. 
Figure 4a. Co-polarisation Signature of a 
Perfectly Conducting Dihedral Corner 
Reflector. 
Figure 4b. Co-polarisation Signature of 
the Central Business District of Sydney, 
Australia. 
Figure 4c. Co-polarisation Signature of a 
Residential Area of Sydney, Australia 
Normalized Intensity 
(Radar Incidence Angle =60 9 ). 
  
Figure 4b. 
  
   
  
  
  
  
     
      
    
          
   
  
   
  
  
   
    
     
  
  
  
1.0 d 
Tu ru 
8 A 
zo TH or > 
EE : 
zo a ES 2 
> N TH ÿ = 
= 0.4 SN 4 2 
© = 
E 0.2 E 
3 5 
Zz = 
0.0 
n ES “x 
A polarisation signature of the central business district larger or smaller backscatter than expected. These 
(CBD) of the city of Sydney, Australia, is shown in Figure effects are related to building size. 
4b. This area consists of large dense buildings, and the 
radar look direction is approximately normal to these Radar backscatter is a function of many factors in the 
buildings. There is little else in this region (no parks or urban environment, the dominant ones being street 
open space) hence the dominant reflection is from the orientation with respect to the radar look direction, and 
dihedral corner reflector effect. It should be noted that the building bulk. A thorough understanding of these 
pedestal (the vertical distance between zero and the dominant backscattering contributors in a real urban 
minimum backscatter value) of this polarisation signature situation is necessary to enable all factors to be 
is low, implying that there is little diffuse scattering (which incorporated when determining the land use and bulk 
one would expect from vegetation). Although the density of the built environment. Further research needs 
residential area is a mixture of buildings, trees, and parks, to concentrate on multipolarised data and its combination 
the dihedral corner reflector effect is still distinguishable in with visible/near infrared images, as this may provide 
its polarisation signature with the two peaks showing, but extra information to enable an accurate classification of 
it has a higher pedestal than the city (Figure 4c). the urban area. 
SUMMARY AND CONCLUSION REFERENCES 
Unfortunately real urban data is not as easy to predict as Bryan, M. L., 1982. Analysis of Two Seasat Synthetic 
a simple square building. Not only are there dihedral Aperture Radar Images of an Urban Scene. 
corner reflector effects (as in the rectangular building Photogrammetric Eng. & Remote Sensing, 48(1), March, 
above), but there will also be multiple bounce effects from pp. 393-398. 
surrounding buildings and other structures. Single bounce 
effects, from a flat surface near normal to the radar look Deguchi, C., Nakayama, Y., Sugio, S., & Yokota, H., 
direction, also provide a large backscatter response. In 1995. A Study on the Applicability of AMI-SAR Data to 
addition, phase interference effects can occur causing a Land-Use Planning. In: Final Report of JERS-1/ERS-1 
712 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B7. Vienna 1996