Research On Automatic Identification System Search And Rescue Transmitter

In recent years,the maritime transport industry expanded and developed with the rapid development of globalization economic,which making the maritime traffic even more complicated.Collision,grounding,sinking and other accidents have occurred,resulting in significant personal injury and economic loss,and therefore the design and production of sea rescue equipment is very urgent and necessary.AIS is a transponder system for ships intending to increase the safety at sea.It operates in the VHF band.The two frequencies used worldwide are 161.975 and 162.025 MHz(channels 87 B and 88 B,or AIS1 and AIS2).This paper studies the AIS-SART(AIS,Automatic Identification System;SART,Search and Rescue Transmitter).It is a kind of search and rescue transmitter which based on an automatic identification system.An AIS transmitter regularly transmits the ship's position,heading,speed and MMSI(MMSI,Maritime Mobile Service Identify,the unique maritime identification number).This data is received by ships in the vicinity.The data can be plotted automatically on a digital map or radar screen.AIS-SART will alternately send messages that contain location information in the AIS's two channels when someone is in distress.So rescue organization will locate and rescue the goal quickly and accurately to improve the efficiency of the rescue.Based on the analysis of the basic theory of AIS,we analyzed AIS-SART basic principles and performance requirements,and proposed the idea of the design of AIS-SART.The hardware design is divided into four parts: Beidou navigation module,information processing module,control module and the RF transmitter module.Beidou module is mainly responsible for receiving signals from Beidou satellite,containing location,time,speed and other informations.Information processing module is the core module of AIS-SART,which is responsible for analyzing the Beidou positioning information and encoding and encapsulation message by AIS data protocol.The control module is mainly responsible for controlling the start of AIS-SART,transmitter of messages and so on.The RF transmitter module is mainly responsible for the AIS messages emitted by the antenna.Finally,based on this design,produce and test the AIS-SART.Test results verify the correctness and feasibility of this design.