Design of Star Sensor Optical System with Large Field of View and Low Distortion

star sensors is an important part of micro-nano satellite.By means of optical remote sensing technology,the flight attitudeinformation of micro-nano satellite can be inferred.According to the requirements of the star sensor and the parameters of the selected detectorCMV300,an optical system of the star sensor based on the sphere was designed.The optical system consisted of six domestic lenses.Thespectral range was 520～880 nm,the field angle was 18°,and the relative aperture was 1/1.49.The optimized optical system had a focal lengthof 25 mm and a total length of 37.9 mm.It had a very low distortion rate(≤0.12%),energy concentration greater than or equal to 90%(within 2×2 pixel),uniform imaging and good color correction.The results show that the imaging quality of the optical system is good.It can meet therequirements and development needs of star sensors for micro and nano satellites.

Conclusion

This article designs a spherical star sensor optical system, which has a large spectral range (520-880 nm), a large field of view angle (18 °), and a large relative aperture (1/1.49). The optical system is optimized based on 6 improved Pittsburgh objective lenses as the initial structure, all using domestically produced lens materials and using spherical processing to reduce processing cycles and costs. The focal length of the optical system is 25 mm, the rear intercept is 4 mm, and the total length of the system is only 37.9 mm, meeting the miniaturization requirements of the star sensor. In terms of imaging quality of optical systems, the diffuse spots are circular and of consistent size, resulting in uniform imaging. And this optical system has an extremely low distortion rate (less than or equal to 0.12%), which can effectively reduce the angle measurement error of the star sensor. In addition, in 2 × Within the radius range of 2 pixel size, the energy concentration of each field of view angle remains above 90%, with high accuracy in detecting stars and good color correction. Therefore, the design of this optical system is reasonable and can meet the requirements and development needs of micro and nano satellites for star sensors.