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Proceedings Paper

On-orbit calibration of space camera based on stellar image correspondences
Author(s): You Zhai; Luan Zeng; Wei Xiong
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Paper Abstract

At least three stellar images are needed from different points in space with different orientations of the camera and calibration is realized by finding correspondent stars in stellar images. The method doesn't need any knowledge of orientations of the camera and the calibration is only based on the stellar image correspondences. In this method, homography between stellar images induced by stars (called star-homo for short) is used to approximate the infinite homography (called inf-homo for short). It is well known that the inf-homo provides constraints on image of absolute conic (IAC) which is related to camera internal parameters. Therefore, we use star-homo to replace of inf-homo to compute IAC. When IAC is computed, we can decompose camera internal parameters from IAC. When computing IAC, an unknown scale factor exists, this makes the constraints on IAC nonlinear. In order to transform nonlinear equations to linear equations, we precompute the scale factor by initial principal point estimate. The advantage brought by linear equations is that it is easier to calculate and the results are more accurate and robust. The experimental results show that the proposed method is feasible and can calibrate the space camera with high precision. Under 1 pixel star points extraction error, the relative errors of camera internal parameters are below 0.7%.

Paper Details

Date Published: 6 March 2015
PDF: 8 pages
Proc. SPIE 9446, Ninth International Symposium on Precision Engineering Measurement and Instrumentation, 94460R (6 March 2015); doi: 10.1117/12.2180663
Show Author Affiliations
You Zhai, Academy of Equipment (China)
Luan Zeng, Academy of Equipment (China)
Wei Xiong, Academy of Equipment (China)


Published in SPIE Proceedings Vol. 9446:
Ninth International Symposium on Precision Engineering Measurement and Instrumentation
Junning Cui; Jiubin Tan; Xianfang Wen, Editor(s)

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