Design of BeiDou-based Multimode Communication Maritime Search and Rescue Terminal

In order to address the low alarm effectiveness of existing portable maritime search and rescue terminal, this paper develops a multimode communication maritime search and rescue terminal that can issue distress calls using the AIS method and the BeiDou 3 short message function. The AIS alarm protocol is widely used and can quickly alert surrounding vessels to carry out rescue operations for those in distress. When there is no other vessel nearby, Beidou 3 short message is enough to overcome the distance limitation and send the distress alarm signal to the SAR command center through satellite, and then the command center will dispatch the rescue force to carry out rescue, and the combination of the two alarm means can realize the efficient alarm in the global scope. At the same time, the two-way communication function of BeiDou 3 short message can provide feedback to the people in the water about whether the alarm signal is received and the real-time rescue progress, soothing the emotions of the people in distress, which is of great significance to further improve the success rate of rescue.