International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B1. Istanbul 2004 
  
line of sight of the satellite and obtained from Figure 4 by 
expression (1) (Hanssen, R.F., 2001). 
   
  
    
Sat.orbit. North 
Azimuth Look 
Direction 
  
> East 
Satel. line 
of sieht. 
3 € = ws 
Azimuth 
ceri Look 
» East 
Br 
  
  
Figure-4. Projection of the three components of the deformation 
p ; : 
vector d -(d,,d,,d,) onto satellite LOS. (Hanssen, R.F., 
2001) 
d. -d cos, )-sinQ, Jd, cos, —3/2)*-d,sin&, -3z/2] (1) 
Here a, is the azimuth angle of the satellite orbit and is ~190 
degrees for the ERS satellite, 0, is the incidence angle of the 
satellite and is ~23 degrees for ERS. If we consider the fact that 
the North Anatolian Fault is a strike slip fault, the incidence 
angle of the satellite is ~23 for ERS, the vertical deformation is 
very small and we can assume d, =0. 
The amount of deformation in the line of sight of the satellite at 
such a point may be calculated with the formula below, 
d, =-0.0678d, + 0.3848d, (2) 
The GPS values collected before and after the Marmara 
Earthquake of 1999 by two continuous data collecting 
GPS stations, namely DUMT and TUBI erected in this 
region by TUBITAK-MRC EMSRI are given in Table-2. 
  
Deformation 
d, (sn) d, (sn) 
  
  
DUMT {0.010 0.013 
  
  
TUBI 0.010 0.025 
  
  
  
  
Table-2. Coordinate values obtained by two GPS stations 
collecting continuous data. 
Substituting d, and d, deformation values obtained from 
Table-2 into expression [2], d, component of the 
specified point is calculated 0.0043244sn for DUMT 
station and 0.008942sn for TUBI station. If the earth's 
radius is assumed R=6361236m, then we compute 
d, puyn-13.34cm, d,rugy- 27.59cm. Taking these values 
into consideration, definite deformation values for each 
fringe digitized from Figure 3 are entered into the 
database to obtain the absolute deformation map by linear 
interpolation in the sight of the satellite as shown in 
Figure 5. However, fringes on and in the vicinity of the 
fault line were not explicitly obtained because of the 
insufficiency of the wavelength here. These regions are 
therefore masked in the deformation map. 
  
  
    
“ligth 
Directick 
10 cm 
  
  
  
Figure-5. Ground deformation in the satellite LOS 
4. CONCLUSIONS 
Until almost fifteen years ago, the scientists were experiencing 
significant difficulties in application of SAR interferometry 
potentially in various areas either because the technique is 
difficult to comprehend in theoretic basis or unavailability of 
suitable data sets. Although contemporarily significant progress 
has been made on alleviation of these problems still some 
problems exist with regard to phase unwrapping. Therefore, the 
interferogram obtained in this study was visually interpreted 
and the fringes were manually digitized in order to obtain more 
correct results. Since LOS deformations obtained from digitized 
    
   
    
     
  
  
  
   
    
  
    
   
  
   
   
  
  
  
   
   
    
   
   
  
  
  
   
  
  
  
  
  
  
  
   
   
   
  
   
   
   
   
   
   
    
  
   
   
  
    
    
   
   
  
  
  
  
    
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Journal fc 
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Reilinger, 
Lenk, A. 
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Wright, | 
2001. Tri, 
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Lett., 28, 
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