Two-step calibration method for extrinsic parameters of an airborne camera

Area of Science:

• Geospatial Information Science
• Computer Vision
• Robotics

Background:

• Accurate target geo-location is critical for wide-area reconnaissance cameras.
• Existing calibration methods may not meet stringent accuracy requirements.
• Understanding the orientation relationship between camera and frame coordinate systems is essential.

Purpose of the Study:

• To propose a novel extrinsic parameter calibration method for wide-area reconnaissance cameras.
• To accurately determine the orientation relationship between the camera coordinate system (CCS) and the frame coordinate system (FCS).
• To enhance the geo-location accuracy of reconnaissance camera systems.

Main Methods:

• Utilized an extended Kalman filter for calibrating the roll axis between FCS and CCS.
• Employed a combination of least mean square and particle swarm optimization for deducing the pitch axis calibration.
• Performed quantitative analysis via numerical simulation to assess calibration accuracy.
• Conducted experimental validation to demonstrate the method's effectiveness.

Main Results:

• The proposed method successfully calibrates the extrinsic parameters of the camera.
• Numerical simulations confirmed the high accuracy of the calibration.
• Experimental results validated the practical effectiveness of the novel calibration technique.
• The method provides precise orientation determination between CCS and FCS.

Conclusions:

• The novel calibration method effectively addresses the accuracy requirements for target geo-location.
• The integration of extended Kalman filter and optimization techniques offers a robust solution for camera extrinsic parameter calibration.
• This approach significantly improves the geo-location precision of wide-area reconnaissance systems.