International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B-YF. Istanbul 2004 
  
  
  
   
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
2004 
Periodic and random noise can be reduced by increasing the Since atmospheric haze directly affects the histogram of the 
ratio of signal to noise (figure 9) (Abreu ef al 1996, Hu et al image (shift and compression), histogram transformation 
1997, Ishihara ef al 1999). techniques are employed to eliminate it(figure 11) (Mekler & 
could Kaufman 1990). 
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Figure 9. Image No.3 (PAN) after noise removal 
Fundamentally band missing problem could not be eliminated : 
st be ange ay Ssing D d $C maniac Figure 11. Image No.5 (LISSIII) after haze removal 
jacent or improved because of significant loss of data but sometimes 
replacement of values obtained from the correlaton equation to ; : 
à Y 3 4.3 Geometric Quality Improvement 
other bands can be useful however not appropriate for all of the 
features. Geometric Quality improvement methods are listed irtable 6. 
4.2 Atmospheric Quality Improvement = ; : 
p Q y mp Geometric Manual Automatic 
In table 5, removal methods of atmospheric effects are QE Improvement Improvement 
mentioned. Ha Band to band Conformal Sub pixel Edge matching 
misregistration | Transf. & (Canny 1986,Tao & 
Atmospheric Manual Statistical Resampling Huan 1997) 
Problem Elimination Elimination Image to map Rectification Rectification using 
Cloud Cover Cloud masking by | Cloud masking by misregistration | using Manually | template matching 
region growing clustering and selected GCP's technique 
thresholding Table 6. Geometric Quality defects andimprovement methods 
Haze Conventional HMM correction : 
enhancements and stretching Using sufficient and well distributed GCPs, the image can be 
(Andrews 1976) rectified properly and be matched to the overlaid vector map 
Kats Table 5. Atmospheric problems andremoval methods (figure 12) (Buiten 1993). 
ld be 
them Once cloud is recognized, a nullor zero value is assigned to the 
  
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corresponding pixels(figure 10). 
  
Figure 10. Image No.4 (AVHRR) Cloud masked 
  
Figure 12. Image No.6 (MODIS) Image to map registration