Marine Turbulence Laboratory

T-REMUS

UPDATE, 2011: T-REMUS is being upgraded with an IRIDIUM satellite communication system to allow for long-range missions

SMAST's Turbulence REMUS (T-REMUS) is a modified version of Hydroid Inc. standard REMUS - a low cost, light weight, autonomous underwater vehicle which is designed to interface with a Windows laptop computer post-mission to download and subsequently analyze data. More complex than the standard REMUS, T-REMUS is designed to collect a variety of oceanographic data including pressure, temperature, salinity, bathymetry, water velocity, and shear. In addition to instantaneous pressure and temperature T-REMUS also measures their respective gradients.

The onboard navigation system uses Long Baseline (LBL), Ultra-Short Baseline (USBL) acoustic transducers, a Global Positioning System (GPS), bottom lock from an Acoustic Doppler Current Profiler (ADCP), and its internal compass to find its way autonomously (or without post-launch communication with the deployment team) from waypoint to waypoint.

To gather data while the vehicle is under way, T-REMUS is equipped with a team of sensors:

  • Hotel sensor suite, including compass, attitude sensor, and vital vehicle sensors that monitor battery usage, temperature, internal pressure, etc.
  • Sea-Bird SBE 49 FastCAT CTD, provides Conductivity, Temperature, and Depth data at a rate of 16 Hz.
  • Teledyne-RDI 1200 kHz ADCP (Acoustic Doppler Current Profiler), used to monitor water velocity both above and below the vehicle
  • MSTL 900 kHz Side scan sonar, used to create detailed images of the sea floor
  • Rockland Scientific microstructure measurement system, includes 3 axis accelerometer, 2 fast response microstructure thermistors, 2 velocity shear probes, all sampling at 500 Hz.
  • Wetlabs ECO puck, either a BBFL2 which measures backscattering at 650nm, Chlorophyll, and Uranine, a trace dye, or a BB2FL, which measures backscattering at 470nm, 700nm, and Chlorphyll.

The T-REMUS is upgraded often as technology progresses and to reflect the data acquisition needs of the Marine Turbulence Laboratory. In 2009, WiFi capabilities were added to the vehicle. In 2008, the addition of a secondary onboard computer system, called RECON, added the functionality necessary to have the REMUS respond to environmental conditions and/or onboard sensors. The most recent addtion to our arsenal of equipment is a Gateway Buoy. The Gateway Buoy includes an acoustic modem to communicate with the REMUS while underway, a GPS, and a radio link to a computer on ship or shore. If allowed to drift with water current, the buoy communicates its position to the REMUS, which in turn is able to adjust its course and track the drifting buoy. 2011 upgrades include addition of IRIDIUM satellite communications to allow for long-range missions.