Volume 2025, Issue 1 7550238
Research Article
Open Access

On an Autonomous Pulsar Observation–Based Timekeeping Method for Deep Space

Shibin Song

Shibin Song

College of Electrical Engineering and Automation , Shandong University of Science and Technology , Qingdao , Shandong , China , sdust.edu.cn

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Xiaowei Jin

Xiaowei Jin

College of Electrical Engineering and Automation , Shandong University of Science and Technology , Qingdao , Shandong , China , sdust.edu.cn

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Haixia Wang

Corresponding Author

Haixia Wang

College of Electrical Engineering and Automation , Shandong University of Science and Technology , Qingdao , Shandong , China , sdust.edu.cn

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First published: 20 February 2025
Academic Editor: Giovanni Palmerini

Abstract

To provide autonomous and accurate time service for deep space missions, a pulsar observation–based timekeeping method is documented in this paper, which utilizes pulsars as the time information source. Firstly, the pulsar observation noise is remodeled as the combination of the Gaussian noise and colored noise, and the detailed expression of the colored noise is presented in the paper. An improved Grey model (GM) is proposed to describe the onboard clock evolution, which models the grey action quantity as a time-varying coefficient and attenuates the dependence of the model on the initial state. On the basis of the modified observation noise model and GM, an unscented Kalman filtering (UKF) is adopted to estimate the onboard clock error. Numerical experiments are conducted to analyze the validity of the proposed method and the impact of spacecraft positioning error and pulsar selection on the proposed method. The proposed method offers an autonomous solution for onboard timekeeping in deep space missions.

Conflicts of Interest

The authors declare no conflicts of interest.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

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