General Site Design
At each site a Base Station is first installed on an available platform such as a tower or other high point. The base station has a high-speed link back to the mainland and from there back to the Australian Institute of Marine Science (AIMS). For sites close to the coast 3G/4G phone technologies are used, for sites further away a mix of microwave and satellite communications technologies are used.
To create the on-reef wireless network a series of poles are installed, these use spread-spectrum radio or 802.11 wireless networking to communicate with each other and then back to the base station or to any device within range. Typical range over water is around two kilometres from pole to pole and around one kilometre from pole to a buoy.
Finally buoys are moored around the reef near to coral and other areas of interest. The sensors are mounted on the buoys, a smart controller collects the data from the sensors and transmits it to the nearest network pole and then back to the base station and then back to AIMS. One of the poles also has a weather station to collect on-water meteorological data.
Any area covered by the network where 802.11 wireless networking is installed (normally most of the reef lagoon) will have Wi-Fi and (restricted) Internet access. This opens up the possibility of people using the network to connect to their own devices and sensors, for example web-cams, and then being able to access those systems from the Island Research Station or, with security enabled, from their local computer.
- Some instruments are fixed to floating buoys and so will have a constant depth but varying distance above the bottom as the tides change, conversely instruments fixed to the bottom will have a constant distance above the bottom but a varying depth. In most cases depth sensors have been included to allow for the actual depth for any reading to be determined.
- All depths in this document are to Lowest Astronomical Tide or LAT.
- Salinity is measured as conductivity; this must first be corrected for temperature before a salinity reading in PSU can be obtained.