The Complete Indicator System Design Of Shipborne AIS Message

Automatic Identification System (AIS) has been rapidly improved in the past thirteen years since the mandatory installation of AIS required by International Maritime Organization (IMO), which is of great importance as navigational equipment for vessel safe navigation, remote monitoring, efficient management of port traffic, and land and sea search and rescue coordinating. With the increasingly improved technology, AIS system performance is also gradually enhanced.However, quite a few problems still exist after knowing its usage and the actual received AIS messages,for example, all the AIS devices are not in good quality; there are many limitations in the implication of preventing collision at sea and other areas;AIS static information is not input or input inaccurately; voyage related message is not input or updated in time or input inaccurately; AIS message in the dynamic information turns into error message or it is lost, repeated, delayed or its update intervals do not meet the requirements.All these factors probably contribute to unreliable received message, inaccurate message or incomplete message. Though Position Accuracy and Receiver Autonomous Integrity Monitoring (RAIM) in AIS dynamic information can indicate the accuracy of position (or degree of reliability) which is based on the received AIS dynamic information of vessel by the receiver and the complete indication information only includes the accuracy of Global Navigation Satellite System (GNSS)Sensor which mainly adopts GPS/DGPS with an accuracy of 20～30 m/3～10 m (when C/A Code is adopted).When the dynamic information in the receiver is not updated for a long time, if only relying on the indication information from GNSS Sensor to determine the accuracy of target location, it is difficult to meet the requirements of vessels’practical navigation. Concerning these problems above, there is no better solution from the receiver to make complete indication information more reasonable.This thesis aims to make a research on the design of Complete Indication System of AIS Message. First of all,to make an analysis on the AIS message data collected from experimental equipment. Analyzing the unreliability phenomenon caused by the AIS data, five main problems are listed below:AIS static information and voyage related message are not input as required or input inaccurately; messages are repeated or delayed; one message of these collected data is made up of six sentences; dynamic information is lost(incomplete or lost). A analysis of these issues is made in a systematical way and solutions are also given in this thesis. Moreover, the incomplete dynamic information is to be further analyzed and completed for its important role and then shipborne AIS Message Complete Indication System is designed and demonstrated in the Visual Studio 2013 with C# language, including three modules such as alert, indication, completion while completion module adopts Kalman filtering Algorithm to track and predict AIS target and fill in the missing AIS ship position, so the reference and completeness of the information from the receiver can be improved, which is able to provide a clear display interface and give navigator and traffic administration a more reliable framework for making judgments.