Premalatha Balan 
  
be to use the precision estimate based on the input ground control points as the initial estimate and repeating the whole 
process starting from flattening the interferogram. This method may improve the results. Another method is to use a 
different set of ground control points for precision baseline estimation. A combination of any of the above mentioned 
methods may also improve the quality of the final DEM. 
  
1200 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
1200 
1100 1100 
1000 1000 
see 900 
800 800 
S ee S 700 
5 s 
— se = 600 
X i 
€ se C^ se 
400 400 
300 300 
208 200 
a 2000 4000 6000 a 2088 4200 6008 Seen 
Distance (meters) Distance (meters) 
(a) (b) 
1200 1200 voit x 
1100 1100 A 
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= 600 > om. = 
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à se 0 5e. P 
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200 200 T — 
8 2000 4000 6000 8000 e 2000 4000 6000 8000 
Distance (meters) Distance (meters) 
(c) (d) 
Pixel Value 
3 3923 t 3 $ i 
  
a 2000 4000 6000 8000 
Distance (meters) 
(e) 
Figure 8 Profiles for the cross section along East —West direction of the DEMs. (a) Profile for the DEM generated 
using baseline estimate based on orbital information. (b) Profile for the DEM generated using baseline estimate based 
on image offset parameters. (c) Profile for the DEM generated using baseline estimate based on fringe rate method to 
estiamte th eperpendicular component and orbital information to estimate the parallel component. (d) Profile for the 
DEM generated using baseline based on fringe rate method to estiamte the perpendicular component and image offset 
parameters to estiamte parallel component. (e) The profile for the reference DEM 
  
  
  
  
36 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part Bl. Amsterdam 2000.