Research on compensation method for starlight emission accuracy based on star point focal length traversal

Star simulators are essential equipment for ground calibration of star sensors and are widely used in the aerospace field. Aiming at the problem that it is difficult to further improve the emission accuracy of the current star simulator due to the lack of comprehensive analysis of the factors affecting the error, a comprehensive error transfer model consisting of star point position deviation, principal point position deviation, focal length deviation, distortion deviation, and object plane tilt deviation was established. Analyzed the design basis for distortion tolerance of the optical system of the star simulator, and the required distortion tolerance for a 0 - 30 degrees field of view with starlight emission accuracy better than 5 '' , 10 '' , and 20 '' was determined. A mapping model between star point position and starlight emission accuracy has been established, and a compensation method for starlight emission accuracy based on star point focal length traversal has been proposed. Taking field of view of Phi 20 degrees and theoretical starlight emission accuracy better than 16 '' as an example, a stellar simulation optical system has been designed, on this basis, an experimental platform was built and compared with existing unified focal length compensation and star map region partition compensation methods, verifying the performance of the starlight emission accuracy compensation method based on comprehensive focal length. The experimental results show that the maximum error of uncorrected starlight emission accuracy is 82.14". After three corrections using the unified focal length compensation method, the starlight emission accuracy is 15.27". Using the compensation method of star map region partition to achieve a starlight emission accuracy of 13.39". The starlight emission accuracy compensation method based on star point focal length traversal is used after one correction, achieve a starlight emission accuracy of 11.23 '' , The proposed method is superior to existing methods in terms of difficulty and accuracy in correction, and can provide new research ideas and advanced technical means for the development of high -precision star simulators.