A 6m steel pole has been installed within a small bommie in Third Lagoon on One Tree Island as part of the sensor network infrastructure at One Tree Island in the southern Great Barrier Reef off Gladstone, Australia. The sensor-relay pole provides a platform for the installation of sensors to measure and monitor water conditions within the lagoon of One Tree Island. The pole has real time communications using 900MHz spread spectrum radio back to a base station on One Tree Island. The pole is initially configured with a single thermistor string with six thermistors that is located down the outer wall of the bommie into the lagoon and so provides a temperature profile of the third lagoon of One Tree Island. The data is collected every 10 minutes and relayed via the base station to the Data Centre at the Australian Institute of Marine Science (AIMS).The system uses a Campbell Scientific logger into which the sensors are connected. The equipment is serviced every six months with plans to install additional instruments such as pressure and salinity. The pole is available for mounting of additional third part instruments and so forms an infrastructure to support future observational work at the Island.

The Pole is one of three located in One Tree Island, one in each of the main sub-lagoons that make up the main lagoon of the reef. Each pole communicates with the other poles and back to the base station located on the Island using spread-spectrum radios, the base station currently uses a Telstra nextG connection back to the mainland and from there the data goes back to AIMS.The poles have a Campbell Scientific CR1000 logger into which the sensors are attached, the logger stores the data and then forwards it to the base station. The current sensors deployed include thermistor strings on each pole and a Vaisala WXT520 weather station on RP3.

Power SupplyBattery Backed (1 x 33Ahr AGM with Solar Regulator), 4 x 5W Solar Panel Supply.Logger Settings - Pakbus Address - 230Logger Setup as router (isRouter = True)CSDC7 comms board rate set at 34KOver-Reef RF Network - RF411 attached to the CSIO port of the loggerRadio Settings - Active Interface - Datalogger CSDCSDC Address 7Protocol: Pakbus awareRadio Net Address - 0Hop Sequence - 0Power mode - less than 2mA 1 SecondRetry level - Low