Sensor network infrastructure was installed at Lizard Island in the northern Great Barrier Reef off Cooktown, Australia. The infrastructure consists of a base station mounted on the workshop of the Lizard Island Research Station (LIRS), two sensor poles that create the on-reef network and four sensor floats on which the sensors are attached. The network uses both 802.11 links and slower spread-spectrum links between the deployed equipment and a Telstra nextG link back to the mainland.

The sensors deployed consist of a Vaisala WXT520 weather station mounted on RP2, MEA Thermistors mounted on each of the buoys to give surface temperature and a mix of SeaBird SBE37 CTD and SeaBird SBE39 TD via inductive cables / modems on the buoys. Sensor strings (inductive cables) are run across the sea bed to position the instruments in deeper water.

The project looks to deploy sensor networks at seven sites along the Great Barrier Reef to measure a range of physical parameters at a range of scales. The project will install communications, data and platform infrastructure that will support future sensor work looking at biological and chemical parameters.

Sensor Floats:

A round 1.4m yellow buoy has been deployed in the southern part of the main lagoon of Lizard Island to the east of Palfrey Island. The buoy is configured as a sensor-float with a Campbell Scientific logger, spread-spectrum radio and 2.4/5 GHz 802.11 wireless for communicating with the base station (located at the workshop near the Research Station) a surface mounted (60cm under the water surface) thermistor and an inductive modem to support a range of inductive sensors, initially this will be a SeaBird SBE39 measuring temperature and pressure (depth) and a SeaBird SBE37 measuring conductivity (salinity), temperature and depth.

As of August 2010 the inductive sensors are located along a 30m cable that runs north into the main lagoon with a SBE39 located at the base of the buoy and the SBE37 at the end of the sensor run.The unit will be serviced every six months and will be used in the future for attaching new sets of sensors.

The buoy is one of four buoys and two relay-poles being deployed on Lizard Island as part of the GBROOS Project. The design looks to measure the water within the lagoon as well as water impinging onto the reef and potentially any upwelling or movement of warm water that may cause thermal stress such as coral bleaching.

The buoys initially have a Campbell Scientific loggers powered off four 5W solar panels, a wind turbine and one thermistor located at the base of the buoy around 60cm below the water line. The buoys use a Campbell Scientific spread-spectrum radio as well as 802.11 Wi-Fi to talk back to Relay Pole 2 and then to Replay-Pole 1 and then to the Base Station.

Weather Stations on Relay Pole 2:

A Vaisala WXT520 integrated weather station has been installed on RP2, a 6m steel pole which has been installed within the lagoon of Lizard Island on the northern Great Barrier Reef. The sensor-relay pole provides a platform for the installation of sensors to measure and monitor water conditions within the lagoon of Lizard Island. The pole has real time communications using 900MHz spread spectrum radio back to a base station on Lizard Island.

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 Lizard Island and then a Telstra nextG link is used to send the data back to AIMS. Identical weather stations are also on Heron Island (southern GBR), One Tree Island (near by) and Orpheus Island (central GBR). A light sensor is also located on the Island itself to give measures of PAR.

The weather station is to provide on-reef weather conditions to allow the interaction with the atmosphere and the water to be understood. It is NOT set up as a meteorological grade station (for example it is too low to the water) but rather to give an indication of the atmospheric conditions at the surface of the water actually on the reef. If you need meteorological grade observations then use the data available for near by locations from www.bom.gov.au

Power Supply

Battery Backed (1 x 33Ahr AGM with Solar Regulator), 4 x 5W Solar Panel Supply.

Logger Settings -

Pakbus Address - 150

Logger Setup as router (isRouter = True)

SDC7 comms board rate set at 34K

SDC7 neighbours range: 1 - 180

SDC7 Beacon: 3600

Over-Reef RF Network -

RF411 attached to the CSIO port of the logger

Radio Settings -

Active Interface - Datalogger CSDC

SDC Address 7

Protocol: Pakbus aware

Radio Net Address - 0

Hop Sequence - 0

Power mode - < 2mA 1 Second

Retry level - Low

This project is part of the Wireless Sensor Networks Facility (formerly known as Facility for The Automated Intelligent Monitoring of Marine Systems (FAIMMS)), part of the Great Barrier Reef Ocean Observing System project (GBROOS) (IMOS)