Sensors 2014, 14(3), 4914-4931; doi:10.3390/s140304914

Exposure Time Optimization for Highly Dynamic Star Trackers

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Received: 26 January 2014; in revised form: 1 March 2014 / Accepted: 3 March 2014 / Published: 11 March 2014
(This article belongs to the Section Physical Sensors)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: Under highly dynamic conditions, the star-spots on the image sensor of a star tracker move across many pixels during the exposure time, which will reduce star detection sensitivity and increase star location errors. However, this kind of effect can be compensated well by setting an appropriate exposure time. This paper focuses on how exposure time affects the star tracker under highly dynamic conditions and how to determine the most appropriate exposure time for this case. Firstly, the effect of exposure time on star detection sensitivity is analyzed by establishing the dynamic star-spot imaging model. Then the star location error is deduced based on the error analysis of the sub-pixel centroiding algorithm. Combining these analyses, the effect of exposure time on attitude accuracy is finally determined. Some simulations are carried out to validate these effects, and the results show that there are different optimal exposure times for different angular velocities of a star tracker with a given configuration. In addition, the results of night sky experiments using a real star tracker agree with the simulation results. The summarized regularities in this paper should prove helpful in the system design and dynamic performance evaluation of the highly dynamic star trackers.
Keywords: star tracker; highly dynamic; exposure time; star detection sensitivity; star location error
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MDPI and ACS Style

Wei, X.; Tan, W.; Li, J.; Zhang, G. Exposure Time Optimization for Highly Dynamic Star Trackers. Sensors 2014, 14, 4914-4931.

AMA Style

Wei X, Tan W, Li J, Zhang G. Exposure Time Optimization for Highly Dynamic Star Trackers. Sensors. 2014; 14(3):4914-4931.

Chicago/Turabian Style

Wei, Xinguo; Tan, Wei; Li, Jian; Zhang, Guangjun. 2014. "Exposure Time Optimization for Highly Dynamic Star Trackers." Sensors 14, no. 3: 4914-4931.

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