The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part Bl. Beijing 2008 
Figure 1. Up: Raw image data, Bottom: Diagonal line removed 
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Vertical line 
Horizontal line 
Figure 2. FFT filter in frequency domain to remove the vertical 
and horizontal noise line 
b. Non-periodical vertical and horizontal noise 
To remove the non-periodical vertical and horizontal noise line, 
the FFT method in frequency domain has been used. In Figure 2, 
the FFT filter has been analyzed carefully only to remove the 
vertical and horizontal noise line without any blurring. 
Figure 3. Left: Vertical & Horizontal Pattern noise, Bottom: 
Removed by FFT method 
2.2 Non-Linearity 
The Linearity value of the KOMPSAT-2 specification, 4% from 
5% to 95% saturation level, is too high to be accepted by the 
Users. The non-linearity of KOMPSAT-2 image data has been 
analyzed with the uniform areas of several DN values, so that 
three regions for grey level (DN) can be divided in Figure 3. 
The vertical and horizontal noise can be removed with each 
region of the next; 
Region 2: HF NUC in MSC on-board 
Region 1: Algorithm for removing Residual NUC (Vertical 
line); Stronger Non-Linear CCD Response in Region 1 
Region 3: Difference between Even and Odd pixel value 
The non-linearity can affect the next; 
Butting zone 
Vertical & Horizontal line 
MS-band Fluctuation 
Normalization with Video gain & NUC 
MTF Curve 
MTF Correction 
Absolute radiometric Cal/Val 
2.3 Butting zone 
KOMPSAT-2 MSC PAN has three CCDs of 5200 pixels. There 
are two butting zone between CCDs that decrease the brightness 
gradually (Figure 5). Because there is some non-linearity in the 
butting zone, we have developed three more algorithms to 
reduce it; Scatter plot, BSM (Butting zone Smoothing Method) 
and Dispersion method. 
Figure 5. The brightness degradation in the Butting zone 
Figure 6. Up: The butting zone between PAN2 & PAN4, 
Bottom: Corrected 
Figure 4. Non-linearity of KOMPSAT-2 image data 
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