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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. A Vaisala WXT520 integrated weather station has been installed on RP3.
The weather station provides measurement of air temperature (Deg. C.), humidity as
relative percent, barometric pressure (milliBars or hPa), rainfall amount, intensity
and duration, hail amount, intensity and duration (not common on coral reefs!) and
wind speed and direction. The wind speed and direction and processed into scalar and
vector (directional) based readings and presented as 10 and 30 minute averages to
give mean values and maximum values. From these you can get the average wind conditions
at either 10 minute or 30 minute periods as well as the gust or maximum wind conditions.
The weather station is connected via an SDI-12 interface to a Campbell Scientific
CR1000 logger which uses a RF411 radio to transmit the data, every 10 minutes, to
the base station on One Tree Island and then a Telstra nextG link is used to send
the data back to AIMS.
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