A novel combination of technologies assembled by the IMT lab has produced an instrument system (BOA) that can be deployed easily, surveyed accurately and built inexpensively for use in marine and terrestrial environments. The design of the BOA digital electronics allow sensor nodes to include different types of transducers and allows up to 150 nodes to be encapsulated onto a single array cable allowing hundreds of sensor measurements to be collected synchronously at rapid intervals.

The IMT Lab designs of both BOA I and BOA I instruments incorporate high-resolution temperature and pressure sensors.

An individual prototype potted pressure sensor and picture of a complete pressure sensor array (coiled).

 

 

A single frame from a data movie generated from a BOA deployment at Conch Reef, Florida. Data was collected from 100 nodes sampling every 10 seconds over a 3 month period May-July 2003. Temperature data has 0.01 °C resolution and is interpolated over a 4 meter topographic grid from the reef flat at approximately 15m to the base of the reef front at 33m water depth. The image shows temperature fluctuations as a result of cold water flux from an internal tidal bore contacting the reef front

Successful deployments of BOA have generated considerable interest in the marine science community, not only to adopt the present temperature/pressure technology, but to use the BOA technology with different environmental sensors. The BOA I system has been used for a study of the physical hydrography affecting Floridian coral reefs on a 10 second temporal scale over 3 months and a spatial scale from 2 m to 100's of meters. The BOA II system has been used to study the shoaling surface gravity field in the surf zone adjacent to the SIO pier

Of particular interest is the potential to use different transducers with the time-division multiplexed BOA design. In this manner, a BOA array with hundreds of nodes could be produced that include , temperature, oxygen, irradiance, conductivity, and transmissivity sensors at each node at a fraction of the expense of hundreds of commercially available instruments.

 

BOAII node. 2-channel (pressure and temperature) sensor node showing transducers and rugged polyurethane encapsulation onto a cable. A flat tab of polyurethane from the moulding process remains on the node and serves as a mounting point if required.