Sentry Specifications & Sensors
Specifications
| Depth capability: | 6,000 meters |
| Dimensions: | Length: 2.9m (9.7ft) Width (with fins extended): 2.2m (7.2ft) Width (without fins): 0.8m (2.7ft) Height 1.9m (6.1ft) |
| Weight: | 1,300 kg (2,860 lb) without extra science gear |
| Operating range: | Up to 80 km/dive, depending on payload and speed |
| Propulsion: | 4 brushless DC electric thrusters on pivoting wings |
| Energy: | Lithium ion batteries, 13 kWh |
| Bus power: | 48-52 Volts DC |
| Endurance: | Up to 36 hours survey time, depending on speed |
| Recharge time: | 10 hours (16 hours total turnaround) |
| Descent/Ascent speed: | ~ 40/55 m/min, 2400/3300m/hr (7800/11000 ft/hr) |
| Navigation: | Long baseline acoustic transponders, Doppler velocity log, and inertial navigation system. |
Science & Engineering Sensors
Sentry is equipped with a standard suite of science and engineering sensors. In addition, Sentry is a sufficiently flexible platform that additional sensors can be interfaced by PIs according to their specific interests and scientific needs. All sensors rated to 6,000 meters (19,685 feet) except as noted.
Vehicle Sensors
Pressure: Paroscientific 8B7000-I Digiquartz depth sensor, rated to 7,000 m (23,000 ft)
Teledyne RDI 300kHz Doppler Velocity Log (DVL)
Attitude sensors (pitch, roll, heading), internal
Phins inertial navigation, internal
Geophysical Sensors
Reson 7125 multibeam mapping sonar, 400 kHz, ~ 200 meter optimal swath width
3-axis APS 1520, 10-5 Gauss dual magnetometers
Edgetech 2200M 120/410 KHz sidescan sonar
CHIRP 4-24 KHz subbottom profiler
Oceanographic Sensors
Sea-Bird 49 FastCAT CTD
Seapoint turbidity meter (optical backscatter)
Seafloor photography: 1Kx1K, 12-bit color still camera with strobe, rated to ≥4,500 meters (14,764 feet)
Project-specific sensors interfaced to Sentry by PIs during recent cruise
Eh electrode (Redox sensor) – Dr. Koichi Nakamura, Japan
TETHYS mass spectrometer - Dr. Richard Camilli, WHOI
3-D imaging system - Dr. Oscar Pizzaro, University of Sydney
Chelsea Instruments AquaTracker fluorometer - Dr. Richard Camilli, WHOI
Note: All sensor data are stored on the vehicle and retrieved upon recovery