Survey of technology status and development of all-time star sensors in near-earth space

Star sensors,a kind of attitude measurement equipment with stars as reference sources,are widely used on satellites,missiles,ships and other platforms.For near-earth space platforms that need to work all-time in the atmosphere,such as ships,aircraft,missiles,and high-altitude balloons,star sensors are faced with the difficulty of detecting dim stars against the strong sky background.This paper first describes the basic working principle of all-time star sensors in nearearth space,followed by an introduction of the research status at home and abroad.The main technical approaches are analyzed and summarized,and the development trend is discussed.The analysis results can provide reference for and facilitate the development of all-time star sensor systems in near-earth space.

The near-Earth space all time star sensors, represented by the United States, have been well applied on multiple platforms. In addition to using spectral filtering technology, these star sensors have different characteristics for products from different platforms:
1) Platforms such as sea-based and ground-based platforms are in the strongest sky background during the day, and star sensor systems are less constrained by volume and weight. They can suppress the background through optical systems with large aperture, long focal length, and small field of view.
2) The sky background of aircraft at altitudes of 30-40km is relatively dark, and a medium field of view (3 °) can be used × An optical system of around 3 °, combined with high-performance detectors, enables the detection of multiple stars in an instantaneous field of view.
3) Airborne platforms located at an altitude of 8-10km are constrained by a bright sky background and limited platform resources. They often use small field of view star trackers with scanning mechanisms to achieve full-time detection of stars. Domestic research started relatively late and is currently in the stage of experimental verification. Some airborne products have completed flight tests.