Research Of The Technology Of Jamming And Anti-jamming Of AIS System

Navigational safety and efficiency of navigation are the premises of Marine traffic. But to accomplish this objective, to be able to master the dynamic and static information between the ships is essential. Although today's navigational technology has made great progress, but the collision accident occurred frequently, caused a great threat to the safety of life at sea and the marine environment. One of the main reasons of this phenomenon is because the current aids of ship collision avoidance can not meet the needs of maritime surveillance and communication. At present, the ships use the radar widely, as the method of having dynamic and static information of other ships. The information that provided by radar are limited, can not identify the ship, inform the name and call sign of vessel, and influenced by weather, sea conditions and terrain. International Maritime Organization (IMO) and national authorities through the development and implementation of collision avoidance rules to require mandatory equipped with the necessary aids, AIS is based on those developed from the technology. In order to improve ship safety, operational efficiency and information transmission capability at sea, IMO identified AIS (automatic ship identification system, Automatic Identification System, called AIS) for the future of marine identification, monitoring and communication systems.As a new navigational system, Automatic Identification System has emerged relying on today's communications technology and computer technology. AIS work at the sea VHF band, the main method to launch the ship data is SOTDMA. According to the information at home and abroad, published papers and the technical standards of International Maritime Organization, the article concludes the composition, application and development of the AIS system.The article focused on the SOTDMA agreement of AIS system to explore and study, analysis the work process and the situation of the time slot allocation and management, and do the simulation study modeled the function of the AIS system. Finally, done a study focused on the situation of human intervention to verify whether we can use the artificial methods to intervene the operation of AIS system, so as to broaden the application of the AIS system for the future.The proper uses of the AIS, help to enhance the safety of life at sea, and help to strengthen and improve the safety and efficiency of navigation, and conducive to the direct control of the ship of the port authorities, and conducive to the protection of the marine environment. AIS provides the most reliable and most effective way to carry out the report of the location of ships and other necessary short exchange of information automatically, so that the users and the VTS centers can receive the accurate location information and identification information, greatly improve the safety of navigation.