An On-Orbit Calibration Method of Star Sensor Based on Angular Distance Subtraction

Abstract

Star sensor needs real-time calibration to improve its navigation accuracy. Compared with other parameters, the position of the principal point is more easily affected by the measurement error, which leads to low calibration accuracy. Conventional star sensors on-orbit calibration methods mainly rely on the angular distance(AD) between stars. The observability of the principal point in this method and the calibration accuracy is not as well as that of other parameters. In this paper, an on-orbit calibration method of star sensor based on the angular distance subtraction(ADS) is proposed. The accuracy of the on-orbit calibration is improved by increasing the observability of the principal point in the calibration process, and the feasibility of this method is verified by the observability analysis. Finally, improved angular distance subtraction(IADS) models are proposed to solve the time-consuming problem of ADS method. In order to demonstrate the performance of the IADS models, simulation calibrations are conducted. The results show that the accuracy of u0 and v0 of the IADS method is 62.7% and 15.9% higher than that of AD method when other parameters are set as nominal values. The calibration accuracy of the principal point is improved effectively.

Error suppression method of SINS/CNS integrated navigation based on diametrical stargazing

“…Following the launch of the star sensor, the parameters of the star sensor will alter owing to the vibration, impact, and changes in the working environment during the launch process [14,15]. The internal parameters of the star sensor will be recalibrated through the autonomous calibration technology, after the launch, to ensure its accuracy and reliability [16,17].…”

Attitude Correlated Frames Based Calibration Method for Star Sensors

“…The iteration calibration method, which considers the weight of different stars, is proposed in [ 18 ]. In addition, an angular distance subtraction on-orbit calibration method is presented in [ 19 ].…”