AtoN AIS Akari

Zeni Lite launched and demonstrated the world's first AIS unit specifically designed for Aids to Navigation, the Akari-AIS-400 at the IALA Conference in Sydney in March 2002. Since then our AIS AtoN systems have been installed in Europe, Asia, the Americas, the Middle East, and African continent.

Zeni Lite was also the first to announce an FATDMA AtoN AIS transponder, the first to install AtoN AIS on buoys, on lighthouses and on light-beacons, the first to monitor Aids to Navigation over an AIS link, and the first to install and commission AIS weather and tidal message broadcast stations at AtoN sites.

Released in 2005, the Akari-100 product-brought a new standard of capability, with a choice of RATDMA or FATDMA operation, and the ability to broadcast meteorological and hydrological data.

Advancement in technology, enabled Zeni Lite to release the next generation Akari-1D and Akari-3D in 2008.

Following the success of the Akari-1 D and Akari-3D AIS AtoN, Zeni Lite is pleased to announce the new Akari AIS AtoN products, which are smaller and use less power than their predecessor.

The names reflect the types of AIS AtoN defined in the IEC 62320-2 test standard, Akari-1 /1 S being an IEC Type 1 unit, and Akari-3/3S being an IEC Type 3 unit.

Akari offers additional features over the minimum requirements for IEC Type 1 and Type 3 respectively. These products contain an additional circuit board with sensing, computing, and memory components to monitor lantern and power supply operation, send addressed messages with monitoring data, and broadcast meteorological and hydrological messages.

AIS Messages are defined by ITU-R M.1371, and Message 21, "Aids to navigation Report", is for broadcasting by AIS AtoNs to provide navigation information for use by shipping. As well as the identity of the AtoN, the type of AtoN, and its position, this message carries a digital flag to indicate if a floating AtoN is off position. All the Akari AIS AtoN units broadcast Message 21 at an interval which is configurable by the authority.

Message 21 will increasingly be an important part of e-Navigation, now being developed by IMO and IALA.

ITU defines Message 6 as an addressed binary message, used for sending of data from one AIS station to another. The Akari uses Message 6 to carry extensive information on the operational status of a lantern and power supply at the Akari unit's location.

The MSG6 format is also compatible with both the Zeni Lite and GLA formats described in IALA Recommendation R0126.

The AtoN authority may have its own monitoring centre, or may assign the monitoring task to a VTS centre or other existing facility. Whatever the location, the monitoring data from each AtoN AIS site can be easily transferred to the required point via the AIS network. Early indication of fault or failure of a lantern or power supply allows the authority to respond rapidly, increasing the availability of the AtoN service.

Message 8 is defined by ITU as a broadcast binary message, meaning that it is intended for multiple users. IMO has defined one version of Message 8 for carrying meteorological and hydrological data. Akari can broadcast this message at intervals set during configuration of the unit.

External sensors are, of course, needed for obtaining most such meteorological and hydrological data.

Zeni Lite can provide complete systems.

Zeni Lite has unique external sensor to obtain wave height , period and direction using GPS receiver and patented unique software processes as option, and add this to the broadcast meteorological and hydrological message. User should note that the accuracy of the wave data is affected by buoy motion.

The data display of the Met-Hydro data received from Akari may be on the ECDIS or radar, or on a separate ENC display. At right is an example of parts of an ENC display, showing a portion of the ENC with the AIS AtoN, and the Met-Hydro data display window. This Akari unit is part of an extensive AIS AtoN and AIS base station network.

The new products use a nominal supply voltage of 12-VDC or 24-VDC. The advantage lies in two areas, energy efficiency and reliability. Limiting the maximum input voltage to 32-VDC permits a robust design of RF transmitter and power system, resulting in the highest reliability. The other advantage is power drain. Operating in FATDMA mode, with Message 21 sent every 3 minutes, power drain is less than 1.0 Ahr per day. If a different supply voltage must be used, a voltage converter is employed.

The choice of the most suitable Akari product for a given application is influenced by the service required, the existing AIS infrastructure, and sometimes by administrative arrangements for base station networks. The following is for guidance only. Zeni Lite offices and distributors can provide additional advices.