Reflective star sensor

Abstract

The invention discloses a reflective star sensor. The reflective star sensor comprises an off-axis three-reflection optical system, a light shield, a detector and an information processor. The opticalsystem is an off-axis three-reflector system with an intermediate image diaphragm and a Leo diaphragm. The detector is a solid-state imaging device. The information processor is an embedded system with effects of collecting and storing the photoelectric digital images formed by the detector and calculating the outputting attitude information. The reflective star sensor has a series of advantagessuch as a low frequency error of a star sensor caused by no color difference, an extremely small optical axis heat drift caused by an optical machine material with a near zero thermal expansion coefficient and parasitic light eliminating convenience caused by the intermediate image diaphragm and the Leo diaphragm, and the existing star sensor cannot simultaneously have the above advantages.

Description

technical field [0001] The invention relates to a reflective star sensor, which can be applied to the fields of spacecraft attitude measurement and rotation angular rate measurement. Background technique [0002] At present, star sensors are often used for attitude measurement of spacecraft. The main principle of this sensor is: using the law that the position of stars is basically immobile relative to inertial space, the star map is obtained by photoelectric imaging of stars in a sky area, and then the star sensor The image is processed and identified to obtain the direction of the optical axis of the measurement sensor in the inertial space, and the three-axis attitude of the spacecraft can be obtained by converting the star sensor installation coordinate system on the spacecraft and the spacecraft attitude coordinate system. [0003] In the prior art, the star sensor hardware includes a light shield, an optical system (lens), an electronic system, electrical appliances, a...

AI Technical Summary

Problems solved by technology

[0005] (1) Chromatic aberration is common in transmissive optical systems, and the low-frequency error of the star sensor caused by the chromatic aberration of magnification is difficult to eliminate, and the low-frequency error is the main error that affects the star sensor to achieve very high precision

[0006] (2) Limited by the ability of chromatic aberration correction and the size of the star point, the working spectrum of the transmission optical system used in the existing transmission star sensor should not be too wide. Too wide a working spectrum will cause a large chromatic aberration of magnification The increase in the size of the star point and image spot cannot meet the design requirements of the star sensor. In addition, the narrowing of the working spectrum leads to a decrease in the sensitivity of the star sensor, the quantum efficiency of the detector cannot be fully utilized, and the spectral range of the star catalog is limited.

[0007] (3) The size and weight of the hood of the existing transmissive star sensor is relatively large, the ability to eliminate stray light is limited to a certain extent, and the means of eliminating stray light inside the lens are limited

[0008] (4) Due to the thermal optical characteristics of the existing transmissive star sensor optical system, it is difficult to eliminate the change of the temperature field, and the means of thermal compensation through the optical-mechanical structure are limited, and the position of the imaging star point will be caused when the temperature field of the working environment changes. Drift, causing the optical axis of the star sensor to drift

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