Automatic Identification System (AIS) technology was mandated by the International Maritime Organization (IMO) for carriage on SOLAS vessels weighing 300gt and up, beginning in 2004. This mandate has resulted in new technology for both tracking and communication purposes.
AIS is an integral component of every modern VTS installation; it is also a key component of every modern integrated bridge. AIS has been installed on AtoNs worldwide. This provides real time AtoN off-position warnings, critical weather information, and AtoN light and racon status. The IMO has recently allowed for the introduction of AIS into SART beacons, enabling any SOLAS vessel to be a potential search and rescue vessel.
With the increasing use of AIS, the technology has become an important tool for port security. The AIS used by the United States Coast Guard and other law enforcement branches has been enhanced so that it is capable of fully interacting with the AIS network while providing secure communications between assets. This enables these vessels to track all AIS traffic and, when necessary, to eliminate their own AIS track.
This ‘stealth’ mode can be accomplished in two ways. The first, and most basic, is by operating as a receive-only unit. Many receive-only units have been sold into this market for these purposes. However, this is a limited solution that does not utilise AIS capabilities to their fullest potential. A second, and much more powerful, method allows encrypted messages to be passed between port security assets. These messages can be as simple as position reports or as complex as targets of interest and search and rescue patterns.
The encryption technology is ‘key’ based, offering the ability to securely share data between assets. When the Coast Guard needs to contact nearby Port Authority vessels for an emergency operation a quick distribution of the required key will ensure that all Port Authority and Coast Guard vessels are able to communicate through a secure connection.