Photonics (Sep 2023)
Research on the Detection Method of Projection Stellar Target Simulator
Abstract
The projection stellar target simulator is a stellar target simulator in which star points are projected to be imaged on a fixed plane at a fixed distance. Compared with conventional stellar target simulators, the projection stellar target simulator makes star points visible and provides the necessary condition for a semi-physical simulation test of the star camera. In this paper, the projection stellar target simulator optical system with high-quality imaging is designed by combining the projection technology, which breaks the collimated imaging of the conventional stellar target simulator optical system, and offers a new thought to solve the problem of decreasing the calibration accuracy caused by the influence of the coaxiality and other factors in the stellar target simulator calibrating the star camera. Based on the imaging behavior of the star map, this paper proposes a method to realize the automatic detection of a projection stellar target simulator by using CCD and introduces the composition and working principle of the detection system in detail. According to the imaging characteristics of star points, denoising and threshold segmentation of the star map are carried out, and an improved centroid algorithm is proposed to achieve high-precision positioning of the centroid coordinates of the star points. The measurement model and measuring formulas for the angular distance between stars are established. The error sources of the detection system are analyzed and obtain the theoretical error of 9.22″ for this detection system. The result of an actual test experiment shows that the position error of single star is less than 11″, in line with the theoretical analysis of the error, indicating the detection system has high detection precision and meets the requirement for the detection accuracy of the projection stellar target simulator.
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