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PROPERTY AND REMOVAL OF JITTER IN BEIJING-1 SMALL SATELLITE 
PANCHROMATIC IMAGES 
Qiong Ran a,b ’, Yaobin Chi a,b , Zhiyong Wang b 
1RS A Institute of Remote Sensing Applications, Chinese Academy of Science, 100101,Beijing,China 
b BLMIT Beijing Landview Mapping Information Technology Co. Ltd., 100096,Beijing,China 
Corresponding E-mail : kateeme@ 163 .com 
Commission I, WG-I/6 
KEY WORDS: Beijing-1 Small Satellite, Panchromatic Image, Jitter Removal, Jitter Property 
ABSTRACT: 
Attitude of the Small satellite is prone to be affected by external disturbing factors due to its small inertia. As for Beijing-1 small 
satellite, jitter is induced and exhibited in the images taken while the outside disturbance is intense. The jitter is manifested as jagged 
lines and edges in the images, leading to distortion of geometric property of the objects. In this paper, properties of the Beijing-1 
small satellite jitter are explored based on analyses of affections of attitude jitter with diverse frequency and directions to the 
imaging process. Accordingly an image based jitter removal method is brought up, the proposed method removes jitter effectively 
and can be introduced into practical production process. 
1. INTRODUCTION 
Small satellite has gained universal attention due to remarkable 
advantages including flexibility and low cost, and has become a 
trend for developing of future satellites. However, owning to 
massive application of lightweight materials, inertia of the small 
satellite is greatly reduced, leading to low attitude stability and 
frequent imaging errors. 
Beijing-1 small satellite was launched into the space as a 
member of the Disaster Monitoring Constellation in October 
2005. The panchromatic sensor onboard has 4-meter resolution 
and 24-kilometer swath. Till now, images acquired from the 
satellite have been widely used in agriculture, hydrology, city 
planning, relic protection, 2008 Olympic Game related 
observation and many others. However, at times when the 
attitude is quite unstable, the satellite trembles and causes jitter 
of the onboard camera, thus leading to abnormality of the 
acquired images. Analyses have been done on exploring 
disciplinarian of the jitter and its affections on the imaging 
process 11 ' 2 * * 5 - 1 , however, few researches has been done on 
manifestation and removal of the jittered images. In this paper, 
manifestation and regulation of the jitter in images is explored 
and research on removal of the jitter is conducted. 
2. JITTER AFFECTIONS ON IMAGING PROCESS 
During the on-orbit operation of the satellite, any motivation of 
the components can cause jitter response of the camera. When 
attitude of the satellite is disturbed, the attitude compensation 
module is motivated. In this course, mechanical movement of 
the apparatus and activation of electronical system may lead to 
jitter, even resonance, of the camera. In operation, the jitter is 
stochastic, it can be of various frequency and directions and 
have diverse affections on the imaging process. 
2.1 Affections of Jitter with Different Frequency 
Jitter of any kind can be decomposed into a series of sine and 
cosine waves. Therefore the analyses below are based on 
consideration of simple sine waves. 
Quality reduction status of jittered image varies with the ratio of 
integration time t and T, where T represents period of the jitter. 
If t is larger than T, the jitter is called high frequency jitter. One 
or more jitter cycles are present during the integration time, the 
high frequency jitter expands diameter of the blur circle and 
causes blurring of the image (Figure 1(a)). 
If t is smaller than T, the jitter is called low frequency jitter. In 
this case, the jitter can be taken as linear movement added to 
the imaging process. Motion of the blur circle causes 
degradation of the image. Displacement of every blur circle is 
decided by the place of pixel integration time on the jitter wave. 
The value fluctuates in certain ranges. If swing of the jitter is 
rather large, so is the displacement value, the pixel is likely to 
be deviated from the original place (Figure 1(b)). 
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