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Bootstrap geometric ground calibration method for wide angle star sensors
Summary
This study presents a novel method for calibrating wide angle star sensors without specialized equipment. The technique accurately determines camera focal length and orientation using two images, improving star identification for aeronautics.
Area of Science:
- Aeronautics and aerospace engineering
- Computer vision and image processing
- Optical systems calibration
Background:
- Wide angle star sensors are crucial for aeronautics, offering a broad field of view for star detection.
- Significant lens distortion in wide angle lenses complicates star identification and can lead to algorithm failures.
- Accurate calibration of star sensors is essential for reliable navigation and attitude determination in aerospace applications.
Purpose of the Study:
- To develop a method for calibrating wide angle star sensors without requiring specialized equipment.
- To address the challenges posed by lens distortion in accurate star identification and camera parameter estimation.
- To enable precise geometric calibration of star sensors using readily available hardware.
Main Methods:
- Analyzing two time-separated images from a static camera to estimate focal length and camera intrinsics.
- Employing a RANSAC-augmented Kabsch algorithm for robust camera orientation determination and false identification removal.
- Utilizing identified stars for precise focal length estimation and applying non-linear optimization with a radial search algorithm.
Main Results:
- Demonstrated effective geometric calibration of wide angle star sensors using real hardware.
- Achieved precise estimation of camera focal length and orientation without specialized calibration equipment.
- Validated the methodology on two distinct camera systems, confirming its practical applicability.
Conclusions:
- The developed algorithm provides a precise and accessible method for geometric calibration of wide angle star sensors.
- This approach overcomes the limitations of specialized equipment, making accurate calibration more feasible for aeronautical applications.
- The study highlights the potential for improved star identification and navigation accuracy through robust sensor calibration.
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