A New AIS-Based Way to Conduct OLAP of Maritime Traffic Flow

Traditional ways of maritime traffic flow investigation include visual observation, radar scan, and aerial photography, etc. However, they have weaknesses such as time-consuming, laborious, data processing problems, biggish error, being difficult to continuously conduct real-time observation, easily being affected by weather conditions and geographical location, etc. AIS (automatic identification system) is a new kind of maritime communication and navigation system, it includes navigation information (ship identity, location, course, speed and etc.) which can be automatically exchanged between vessels, vessels and coastal stations. It is an important technology means to help avoid ship collision. But in recent years, AIS has been applied to many new areas, including VTS, tracking line drawing, ship grounding alert, maritime accident investigation, etc. This paper proposes a new AIS-based way to conduct investigation and online analytical processing (OLAP) of maritime traffic flow. There are three steps here. Firstly, receiving AIS information in different locations by AIS receivers and INTERNET in real time and putting it into ORACLE database. Secondly, obtaining the basic data of the data warehouse for traffic flow analysis by preprocessing which includes data filtering, data extraction and data reduction. Thirdly, conducting OLAP based on time, ship type, navigation direction, speed level and other dimensions. Content of this article includes research background, technical route, technical realization, OLAP instance, and conclusion.