ROVDOG

Seafloor gravimeters and pressure sensors in a common instrument frame with external power and communication cable.
Quad Geometrics

ROVDOG III.5

System features

  • 5 pressure cylinders in a frame
  • Each cylinder contains a gravimeter, a water pressure sensor, gimbals and electronics
  • Gravimeters are of type Scintrex CG-5 or CG-6
  • Water pressure sensors are of type Paroscientific Digiquartz 31K, 42K or higher depth rating
  • Cable to ROV provides power and two-way communication
  • Operator on the vessel controls data acquisition and recording

Benefits of smaller units and increased number of sensors compared to older ROVDOG versions

  • Higher precision with the same number of measurements
    • Gravity drift errors are effectively reduced by averaging
  • Similar precision with fewer measurements
    • Resulting in shorter survey time and lower cost

Specifications

  • Frame height 850 mm
  • Frame diameter 692 mm
  • Weight in air 120 kg
  • Weight in water 15 kg (adjustable)
  • No. of units in the frame 5
  • Unit height 557 mm
  • Unit diameter 203 mm
  • Gravimeters of type Scintrex CG-5 or CG-6
  • Repeatability (Scintrex statement): 5 µGal for single sensors
  • Repeatability (Quad statement): <1 µGal for 5 sensors (standard deviation)
  • Depth rating of cylinders 1500 m or 3000 m
  • Depth rating of pressure sensors 680 m, 1370 m, 2060 m or 2750 m
  • Sampling interval 6 Hz / 10 Hz
  • Integration length 1/6 s – 1/10 s
  • Memory capacity: No internal memory, continuous recording on the vessel
  • Battery life: Backup batter > 2 hours
ROVDOG III.5
quad staff working on the first rovdog iii.5 launch