Time-difference-of-arrival positioning based on visible light communication for harbor-border inspection

Area of Science:

• Maritime surveillance
• Robotics
• Optical positioning systems

Background:

• Port ship supervision is complex and affected by electromagnetic interference.
• Existing maritime target location methods lack efficiency and accuracy.

Purpose of the Study:

• To propose an efficient system for locating maritime targets using UAV and VLP.
• To develop advanced positioning algorithms for improved accuracy and robustness.

Main Methods:

• A UAV equipped with a rotatable receiver and five photodetectors (PDs).
• Chan-Taylor (CT) method based on time difference of arrival (TDOA).
• Two-step weighted least squares (TWLS) for initial estimates, iterative error correction, weighted centroid CT (WCCT), and restricted-region fingerprinting CT (CT-RFP).

Main Results:

• CT method significantly improves positioning accuracy compared to previous methods.
• CT accuracy is 49.71% better than TWLS.
• WCCT reduces maximum error from 8.65 to 6.91 cm.
• CT-RFP achieves millimeter-level accuracy even in high noise.

Conclusions:

• The proposed UAV-VLP system with CT positioning methods offers efficient and accurate maritime target localization.
• WCCT and CT-RFP effectively mitigate positioning errors and enhance robustness.
• This system is suitable for complex maritime inspection environments.