Construction of a marine traffic monitoring system around the world

Recent advances in information and communication technologies are leading to an environment where marine traffic (i.e., locate and track vessels) can be monitored in real time. For larger vessels, position information is collected by sniffing messages of AIS (Automatic Identification System), which they are obliged to install. However, for smaller vessels, such as fishing and pleasure boats, a lack of position information complicates the task. Such vessels rarely install AIS because (1) they are not required to install so and (2) AIS transmitters can be prohibitively expensive for them. Thus, very little progress has been made toward the coordinated utilization of position information by both large and small vessels. Here, we developed a system that enables position information for all types of vessels, large and small, to be efficiently collected and utilized in a coordinated manner. With regards to large vessels, the system utilizes AIS data, just as conventional marine traffic monitoring systems do. With regards to small vessels, the system utilizes smartphones and 3G wireless devices. In this paper, we describe the configuration of our system for the acquisition and coordinated utilization of position information, and discuss its smartphone-based application to collision avoidance in the Tsugaru Strait and navigational safety support in Osaka Bay.