Design of Performance Test System for Star Sensor with Adjustable Background

In this paper, in order to solve the problem that the existing star simulators cannot simulate the sky background change, a star simulator with variable background is proposed to test the performance of the star sensors. Off-axis reflection collimating optical system is designed, by introducing a semi-inverse semi-lens in the main optical path to produce two conjugate focal planes, the star-point reticule and the stray diaphragm are illuminated by two integrating spheres in the stellar source simulator and the background source simulator, respectively. Real-time monitoring of the irradiance at the outlet of the integrating sphere, and the output power of the light source can be controlled according to the needs of star and background brightness. After the two beams merge, they become parallel light through the collimating optical system and are finally received by the star sensor, thus realizing the simulation of stars with variable starry sky background and apparent magnitude. The test results show that the apparent magnitude of the system can be adjusted continuously from-2. 00-6. 00, the apparent magnitude simulation accuracy is 0. 30, and the uniformity of the background light source is97. 3%. The system can well simulate the background changes of stars when the star sensor is running, and can effectively improve the performance test accuracy of the star sensor.

A star sensor performance testing system with adjustable background has been developed based on the background light interference problem encountered in the all-weather operation of star sensors. The adjustable star light source simulator and the adjustable background light source simulator provide constant stars and adjustable sky backgrounds, respectively. The two beams of light are combined through a semi reflective semi lens and imaged into parallel light by a large aperture collimator. By changing the power of the light source and the size of the aperture, precise adjustment of the apparent magnitude and background irradiance can be achieved. The experimental results show that the system can achieve accurate simulation of apparent magnitude within the range of -2.00 to 6.00, with simulation accuracy better than 0.30 and background irradiation uniformity better than 97.3%. It achieves accurate simulation of star images under variable sky backgrounds and increases the authenticity of star simulation. This has certain reference significance for improving the ground performance testing accuracy of star sensors.