On-orbit efficient calibration method for remote sensing camera based on trace invariance.

Area of Science:

• Spacecraft engineering
• Optical instrumentation
• Astrophysics

Background:

• On-orbit calibration of space cameras is crucial for maintaining imaging quality and navigation accuracy.
• Conventional methods using star angular distance invariance are computationally intensive and difficult to implement on resource-constrained spacecraft.
• Limited computational and storage resources on spacecraft pose significant challenges for complex calibration algorithms.

Purpose of the Study:

• To propose an efficient and computationally feasible on-orbit calibration method for space cameras.
• To address the limitations of traditional calibration techniques in resource-constrained environments.
• To improve the accuracy and efficiency of space camera optical parameter estimation.

Main Methods:

• Developed an efficient calibration method centered on calculating the trace of a star matrix derived from observed star vectors.
• Utilized a sequential extended Kalman filtering algorithm to avoid high-order matrix inversion, suitable for autonomous spacecraft operation.
• The core computation involves scalar addition, significantly reducing complexity compared to matrix operations.

Main Results:

• The proposed method demonstrates high computational efficiency and calibration accuracy.
• Internal calibration effectively minimizes imaging distortion.
• An accurate mapping relationship between imaging points and target observational directions is established.
• Sequential extended Kalman filtering enables quick and efficient optical parameter estimation.

Conclusions:

• The novel calibration method offers a practical solution for space cameras, overcoming computational and resource limitations.
• It significantly enhances imaging quality and navigation accuracy for space missions.
• The method is well-suited for autonomous operation on spacecraft with stringent resource constraints.