about performing TDI when satellite has no 
attitude fluctuation, about performing TDI 
without detection and correction, and about 
performing TDI with detection and correction. 
In the same way, the relationship is shown in 
Fig.13(b) when satellite's attitude fluctuation of 
roll and pitch at the same time. 
  
  
—&— TDI (no fluctuation) 
—&8— TDI with correctoin 
(fluctuation) 
—A— TDI without correction 
(fluctuation) 
[. du 
  
> c © 
TTT 
ovement ratio 
[^] 
Lt 
pr 
  
S/N im 
— qm 
UE 
f 
0 10 20 30 40 
integration times 
  
  
  
  
  
(a) fluctuation at roll axis 
  
  
—&— TDI (no fluctuation) 
—B— TDI with correction 
(fluctuation) 
—£&— TDI without correction 
(fluctuation) 
F7] 
VUN RE 
  
  
  
  
S/N improvement ratio; i+ | 
10 20 30 40 
integration times 
  
  
  
(b) fluctuation around roll and pitch axis 
Fig.13 The ratio between integration and S/N 
improvement. 
From the ratio between integration and S/N 
improvement in Fig.13, the S/N improvement 
with TDI with correction when satellite has 
attitude fluctuation can be acquired as same as 
with TDI when satellite has no attitude 
fluctuation. 
5.CONCLUSION 
In this paper, we proposed a image S/N 
improving method which corrects the 
movement due to satellite attitude fluctuation 
in high resolution earth observation systems. 
Numerical analysis and simulation results. 
clarified that the proposed method can improve 
the image quality without increasing the 
diameter of optical devices. 
REFERENCE 
[1] H.Koshiishi. Why the push-broom scan, and 
its limit. Journal of the Japan Society of 
Pohotogrammetry and Remote Sensing, 
vol.31.No.1. pp.15-21 (Jan.1992). 
[2] R.Nagura SN Improvement Ratio by Time 
Delay and Integration for High-Resolution 
Earth Observation System. Electronics and 
Communications in Japan, Part 1, Vol. 78, 
No.3, 1995 
[3] Burello M..Polle B. and Perez E. Fight 
results of the SPOT attitude and orbit 
control system ” ,American Astronatural 
Society, AAS 87-53 (Feb.1987) 
Acknowledgment 
The authors wish to express our deep 
gratitude to Dr. N. Matsui, Dr. M. Morimoto, 
Mr. K. Adachi, and members of the laboratory 
in Department of Computer Engineering 
Faculty of Engineering Himeji Institute of 
Technology for their encouragement. 
22 Intemational Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 7, Budapest, 1998 
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