Global maritime distress and safety system (gmdss): this is a system mandatory by the international maritime organization, including very high frequency radiotelephone (vhf), medium/high frequency radiotelephone (mf/hf), satellite communication equipment, etc., to ensure that ships can operate in any sea area. distress alarm, search and rescue coordination and safe communication can be carried out. satellite communication: including inmarsat, iridium and other systems, providing voice, data, fax and internet access services to realize real-time communication between ships and shores. automatic identification system (ais): automatically broadcasts and receives ship dynamic, static and voyage-related information, improves mutual identification capabilities between ships and between ships and shores, and reduces collision risks. emergency radio position indicator beacon (epirb): automatically or manually activated in case of distress to send distress signals and ship position information to the search and rescue coordination center via satellite. search and rescue radar transponder (sart): it is activated in distress, and it is displayed on the radar screen after being detected by the search and rescue radar, which is convenient for the location of search and rescue ships or aircraft.
