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ABSTRACT: Subpixel centroid estimation is the most important star image location method of star tracker. This paper presents a theoretical
analysis of the systematic error of subpixel centroid estimation algorithm utilizing frequency domain analysis under the consideration
of sampling frequency limitation and sampling window limitation. Explicit expression of systematic error of centroid estimation
is obtained, and the dependence of systematic error on Gaussian width of star image, actual star centroid location and the
number of sampling pixels is derived. A systematic error compensation algorithm for star centroid estimation is proposed based
on the result of theoretical analysis. Simulation results show that after compensation, the residual systematic errors of
3-pixel- and 5-pixel-windows’ centroid estimation are less than 2×10−3 pixels and 2×10−4 pixels respectively.
Keywordsstar tracker-star image location-subpixel centroid estimation-centroid algorithm-frequency domain analysis-systematic error compensation
Science China Technological Sciences 04/2012; 53(11):3145-3152. · 0.75 Impact Factor
