Research On The Validity Of AIS Message Parameters

Since the International Maritime Organization(IMO)compelled the vessel to install the Automatic Identification System(AIS),The AIS has played an important role in the protection of the ship navigation safety and the marine environment.AIS can automatically broadcast and receive the dynamic information,static information,voyage information and security information of the ship,AIS realizes the mutual recognition,collision avoidance and traffic management between ship to ship and ship to shore.However,the error configuration of AIS related message can directly affect its function,and may even cause maritime accidents,which may affect the safety of vessel navigation.Therefore,the validity analysis system of AIS message parameters is developed in this paper,and the present validity of AIS message parameters in a certain sea area is evaluated.In this paper,based on the Oracle database the AIS message validity analysis system is designed and developed firstly.This system is mainly composed of 3 parts:data analysis and process:ing service software,AIS database system,graphics rendering software.The data analysis and processing software completes the detection,analysis and processing of the data file,realizes the filtering and decoding of the AIS message by using multithreading technology,and stores the message in the Oracle database.The AIS database system based on the Oracle11gR2 of the Redhat6.2 is designed,the design of the database table space,table and partition is completed.Based on this system,the specific analysis of the parameters such as MMSI,SOG,latitude and longitude,actual course,rotation rate and so on are realized.A graphic drawing software is designed,and the analysis results can be visualized through this software.In order to improve the efficiency of database access,a efficient access technology of the batch data is researched and optimized.The optimization of the database is studied from two aspects:the storage data and the analysis data.According to the actual test results,the database is optimized and improved.The optimization results show that the data storage speed is doubled,the data analysis rate is ten times higher than before.