Design of BDS Differential Positioning System Based on AIS

Aiming at the problem that automatic identification system (AIS) does not support differential data transmission of Bei Dou navigation satellite system (BDS). This paper starts with the study of AIS communication protocol and Global Navigation Satellite System (GNSS) differential message analysis method, uses AIS communication channel to carry out differential data transmission of BDS, designs a BDS differential positioning system based on AIS, and verifies the feasibility of transmitting BDS differential data through AIS. The experimental results show that the designed AIS-based BDS differential positioning system can realize BDS differential positioning through AIS equipment without a special GNSS differential receiver, and its positioning accuracy reaches meter level, which significantly improves the positioning accuracy of AIS equipment.