Estimation of degradation parameters of smearing star image based on motion trajectory of star’s centroid

Star' s gray intensity wouldn' t follow 2-D Gaussian distribution when the rotational velocity exceeded the highest rotational velocity which would affect the processing precision of centroid of star spot. The analytical solution of motion trajectory of star' s centroid was simplified considering that the exposure time was short enough, and then the precision of the linear approximation was analyzed through simulation. The character of gray intensity of smearing star was analyzed based on the simplified trajectory, then a novel algorithm was proposed to estimate the degradation parameters of smearing star image. Through simulation and experiment, the validity of the proposed algorithm has been testified, the largest error of estimated blur length is around 0.8 of a pixel, while error of the estimated blur direction is about 2, feasibility of the proposed method has also been validated through simulations.