The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part Bl. Beijing 2008 
Fig.7 Simulation result when the accuracy is 2% 
The simulation has been done with other accuracy and the 
statistical results are shown in Table 2. 
Relative calibration 
accuracy(%) 
0.5 
1 
1.5 
2 
3 
4 
PSNR 
50.0 
44.3 
40.9 
38.5 
35.0 
32.5 
Table 2. The influence on image quality under different 
calibration accuracy 
The image is clear when the calibration accuracy is 2%. There 
are some strips in the homogeneous area of the image when the 
calibration accuracy is 3%, but it is not obvious. When the 
calibration accuracy is 4%, the strips in the homogeneous area 
are obvious. 
Fig.8 Simulation result when the accuracy is 3% 
Other images have also been used as the input images and the 
simulation results are nearly the same as the results in Table 2. 
PSNR can evaluate the influence properly. The original output 
DN values after being corrected are different slightly from the 
expected values because of the calibration error. The user can 
determine their requirement about relative calibration accuracy 
according to their acceptable DN distortion and the simulation 
results can be referenced. 
4 SUMMARY 
The influence on image quality under different relative 
calibration accuracy is acquired by simulation. Sometimes, an 
image processed with relative radiometric correction still has 
many strips. This phenomenon happens when the calibration 
coefficients are failed and it is not studied in this paper. In that 
case, the user should correct the raw images with other relative 
calibration coefficients again. The simulation results in this 
paper are acquired when the relative calibration and correction 
are both done properly. 
REFERENCES 
Fig.9 Simulation result when the accuracy is 4% 
K. S. Krause, 2006. QuickBird relative radiometric performance 
and on-orbit long term trending. SPIE Vol. 6296