Autoprobe: An autonomous observational platform for microstructure studies

Autoprobe is a general purpose autonomous observational platform with the capability of making Lagrangian measurements of any depth dependent property. Autoprobe can change its displacement in response to internal commands as desired, pneumatically forcing fluid into or out of a bladder. An electronic control system generates the commands from the temperature and pressure measurements, utilizing proportional control with rate feedback. The control system has been programmed to operate in the following modes: (1) to stabilize at a constant pressure, (2) to follow a constant temperature, (3) to make vertical excursions, and (4) to respond to remote control. Acoustic Telemetry is utilized in the instrument yielding navigational information as well as temperature and pressure data. Hydrophones are used with a shipboard recorder for tracking the Autoprobe, enabling the operator to monitor Autoprobe´s performance. Autoprobe has a multi-level safety system allowing it to blow ballast on a time signal or jettison weight if it goes too deep, if a desired time is reached, or if an acoustic command is received from the surface. Autoprobe has been used as an observational platform for a total of 44 dives.