A star tracker on-orbit calibration method based on vector pattern match.

Area of Science:

• Aerospace Engineering
• Astrodynamics
• Optical Instrumentation

Background:

• On-orbit calibration is crucial for maintaining star tracker attitude accuracy.
• Existing calibration methods exhibit poor performance, particularly in estimating the principal point location.
• Principal point estimation errors introduce significant bias into attitude determination.

Purpose of the Study:

• To develop a robust on-orbit calibration method for star trackers.
• To accurately estimate the principal point location, a critical yet challenging parameter.
• To enhance the overall attitude accuracy of star trackers.

Main Methods:

• A novel on-orbit calibration method based on the vector pattern match criterion.
• Initial estimation of the principal point location using the proposed criterion.
• Subsequent update of other model parameters via maximum likelihood estimation.
• Incorporation of multiple succeeding frames optimization and star density weighting for robustness.

Main Results:

• The proposed method demonstrates validity through simulations and night sky observations.
• It significantly outperforms least squares and Samaan's methods, especially with poor initial principal point guesses.
• The method effectively addresses the challenge of principal point location estimation.

Conclusions:

• The developed on-orbit calibration method enhances star tracker attitude accuracy.
• It provides a robust and effective solution for estimating the principal point location.
• This advancement is vital for precise attitude determination in space missions.