DETECTION AND CORRECTION METHOD OF ATTITUDE FLUCTUATION OF 
SATELLITE AND S/N IMPROVEMENT USING MULTIPLE LINERAR ARRAY CCD 
Riichi Nagura, Ryouichi Sakaguchi 
Department of Computer Engineering 
Faculty of Engineering 
Himeji Institute of Technology 
2167 Shosha, Himeji,671-2201,Japan 
E-mail: nagura@comp.eng.himeji-tech.ac.jp 
Commission VI Working group No.1 
KEYWORDS: Signal-to-noise improvement ratio, Attitude fluctuation of satellite, 
Time delay integration 
ABSTRACT 
The improvement of the image quality is one of the most important issues for the high resolution 
earth observation system. A time delay integration method combining plural CCD output signals 
provides the solution for acquiring high quality images without increasing the optical diameter. 
The attitude fluctuations of satellite degrade image quality when adopting a time delay integration. 
Then this paper describes the results of correction of attitude fluctuation of satellite when adopting 
a time delay integration method by simulation analysis. 
1.INTRODUCTION 
The improvement of the signal-to-noise ratio 
(S/N) is one of the most important issues for 
high resolution earth observation system.[1] 
The signal input level from the surface of the 
earth rapidly decreases in the high resolution 
earth observation system. Consequently the 
amount of random noise relatively increases in 
observed image data. In order to improve S/N of 
the image, a large optical device is required. 
But it is difficult to load large optical devices 
into satellite. 
To improve the image S/N without increasing 
diameter of optical devices, multiple linear 
array charge-coupled device (CCD) method [2] 
has been studied. This method uses multiple 
linear array CCD, and performs a time delay 
integration (TDI) method to acquire S/N 
improvement. 
But in this method, the satellite's attitude 
fluctuation degrades the image quality. 
In this paper. we detect the satellite's 
attitude fluctuation from relational output 
signals of plural CCD and correct the image 
deterioration due to satellites attitude 
fluctuation. After this correction, we perform 
TDI method and acquire the high quality 
image. 
2.MULTIPLE CCD IMAGING 
2-1. THE PRINCIPLE OF TDI 
TDI is the system of arranging in the 
multiple linear array CCD perpendicular to the 
direction of satellites movement in the focal 
plane of the optical system as shown in Fig.1. It 
increases the signal amount and the S/N by 
synthesizing an output of each linear array 
CCD. 
16 International Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 7, Budapest, 1998 
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