Use of the automatic identification system (AIS) on autonomous weather buoys for maritime domain awareness applications

The United States Coast Guard (USCG), as part of the Department of Homeland Security, is responsible for a wide variety of missions in the maritime domain. In order to support the accomplishment of these missions, the USCG needs to collect as much information as possible on activities occurring in the maritime domain. A large part of maritime activity relates to the movement of vessels. Therefore, detection, classification, identification and monitoring of vessels are a key component of what is known as Maritime Domain Awareness (MDA). The Automatic Identification, System (AIS) is a technology that is used primarily as a tool for maritime safety, including vessel collision avoidance and as a :means for coastal nations' Vessel Traffic Services (VTSs) to get information on vessels operating near their coasts. AIS equipment aboard vessels continuously and autonomously transmits information about the vessel including its identity, position, course, and speed to enhance safety. These transmissions can be received by other vessels or by land-based stations equipped with AIS receivers. The USCG sees the capability AIS provides, particularly for vessel tracking, as a major contributor to MDA and VTS. To extend the capability of USCG land-based AIS monitoring stations further offshore, the USCG Maritime Domain Awareness Program Integration Office sponsored the development of a near real-time, autonomous automatic identification and telemetry system based on AIS technology for installation on National Oceanic and Atmospheric Administration (NOAA) weather buoys through the National Data Buoy Center (NDBC),and its technical support contractor, Science Applications International Corporation (SAIC). This paper discusses system design of a prototype, autonomous, buoy-based, embedded system for AIS-equipped vessel detection using an AIS receiver and satellite transmitter for near real-time relay of vessel identification data. This paper also describes follow-on enhancements to the system to further extend AIS coverage and field testing of the system. The prototype system development began in August 2004. The prototype system receives AIS data from AIS-equipped vessels on a timed, periodic schedule, processes and verifies received data onboard the buoy, and relays these data from the remote weather buoy via satellite in near real-time to the NDBC Data Assembly Center (NDAC), and then on to the USCG. The prototype system was successfully field tested March 2005 through June 2005 on four near-shore NDBC buoys located in the Strait of Juan de Fuca, near San Francisco Harbor, near Charleston, South Carolina and near Cape Cod, Massachusetts. Field testing successfully proved the concept of collecting vessel identification data from an autonomous AIS system on NDBC weather buoys. Enhancements to the system were developed from August 2005 to February 2006. These enhancements extend AIS monitoring coverage from periodic AIS monitoring to continuous monitoring and conserve system power by insertion of NDBC weather data into the AIS data stream returning it to NDBC using the low power satellite telemetry of the AIS system rather than the existing high power geosynchronous satellite transmission system in use on most NDBC weather buoys. Extended field testing of the enhanced AIS system on four deep ocean NDBC weather buoys began in March 2006 and will continue through February 2007. The installation of an AIS system on NDBC weather buoys provides additional platforms for the use of AIS by the USCG in support of all national maritime missions. The system also provides an opportunity for NDBC to increase the temporal sampling of environmental data from buoys with the system installed as a result of the increased bandwidth available using the satellite transmitter that is part of the buoy-based AIS system and and to broadcast weather data directly to nearby vessels using the AIS. Efforts presently underway through the International Electrotechnical Commission (IEC) to develop standards for real-time broadcast of environmental data over AIS marine bands to vessels using an environmental data message standard under development by the International Maritime Organization (IMO) presents NOAA/NDBC with the opportunity to provide real-time environmental data directly to passing vessels in the near future.