Abstract: An above deck unit for an AIS (automatic identification system) is externally installed on a ship. The above deck unit includes a radio circuit and an associated antenna for transmitting and receiving a message, a position detector and an associated antenna, associated controller and power supply, and a container for storing these elements. An inboard transmission path, e.g., a cable, connects the outdoor unit for the AIS and an AIS display serving as an interface means for the crew. A signal to be transmitted through the inboard transmission path is a processed, for example, an amplified signal, rather than an unprocessed output of a VHF antenna. Therefore, problems of signal loss or degradation along the inboard transmission path are unlikely to occur. Because the unit is incorporated within a single container, it can easily be installed and transferred. With this antenna complex, it is also possible to suppress interference between antennas.

Abstract: An above deck unit for an AIS (automatic identification system) is externally installed on a ship. The above deck unit includes a radio circuit and an associated antenna for transmitting and receiving a message, a position detector and an associated antenna, associated controller and power supply, and a container for storing these elements. An inboard transmission path, e.g., a cable, connects the outdoor unit for the AIS and an AIS display serving as an interface means for the crew. A signal to be transmitted through the inboard transmission path is a processed, for example, an amplified signal, rather than an unprocessed output of a VHF antenna. Therefore, problems of signal loss or degradation along the inboard transmission path are unlikely to occur. Because the unit is incorporated within a single container, it can easily be installed and transferred. With this antenna complex, it is also possible to suppress interference between antennas.