Tracking Efficiency Improvement According to Incident Beam Size in QPD-Based PAT System for Common Path-Based...

Area of Science:

• Optical communication
• Aerospace engineering
• Robotics

Background:

• Unmanned aerial vehicles (UAVs) require high-capacity data links for advanced applications.
• Free space optical (FSO) communication offers a solution for large bandwidth needs.
• Effective pointing, acquisition, and tracking (PAT) systems are crucial for robust FSO links between terminals, especially mobile ones like UAVs.

Purpose of the Study:

• To develop a common optical-path-based FSO communication system specifically for UAV applications.
• To create an efficient and optimal PAT system that reduces structural complexity and improves tracking performance.
• To enable robust FSO communication in dynamic UAV environments.

Main Methods:

• Development of a quadrant photodiode (QPD)-based PAT system without a separate beacon subsystem.
• Implementation of a linearized control strategy based on incident beam size on the QPD for enhanced observability and controllability.
• Verification through optical simulation and experimental testing.

Main Results:

• The QPD-based PAT system demonstrated up to 4.25 times faster tracking performance compared to conventional systems.
• The FSO link achieved 1.25 Gbps full-duplex, error-free communication over a 50 m distance.
• The system showed improved tracking efficiency with reduced size, weight, and power (SWaP).

Conclusions:

• The proposed common optical-path FSO system with a QPD-based PAT is effective for UAV applications.
• The simplified PAT design enhances tracking efficiency and robustness in dynamic environments.
• This technology enables high-speed, reliable optical communication for UAVs.