Acoustic Doppler Current Profilers (ADCP)

Acoustic Doppler Current Profilers

RDI Acoustic Doppler Current Profilers

RDI Workhorse Monitor 300kHz, 600kHz, 1200kHz ADCP

The RDI Workhorse Monitor ADCP can be configured to monitor water currents at frequencies of 300, 600 or 1200 kHz. These instruments also include sensors for temperature, pressure, tilt and compass heading. RDI ADCPs use four beams to measure current velocity, with one of the four transducers serving as a redundant sensor. Through this redundant design, the fourth beam/transducer can substitute for a blocked or damaged beam or it can be used to increase data accuracy.

RDI Workhorse Long Ranger 75kHz ADCP

The RDI Workhorse Long Ranger 75kHz ADCP measures water currents at ranges up to 600m. These instruments also include sensors for temperature, pressure, tilt and compass heading. RDI ADCPs use four beams to measure current velocity, with one of the four transducers serving as a redundant sensor. Through this redundant design, the fourth beam/transducer can substitute for a blocked or damaged beam or it can be used to increase data accuracy.

RDI Quartermaster 150kHz ADCP

The RDI Quartermaster 150 kHz ADCP fills in the gap between RDI's higher frequency 300kHz units and the 75kHz Long Ranger. It measures water currents at ranges up to 340m. This ADCP also include sensors for temperature, pressure, tilt and compass heading. RDI ADCPs use four beams to measure current velocity, with one of the four transducers serving as a redundant sensor. Through this redundant design, the fourth beam/transducer can substitute for a blocked or damaged beam or it can be used to increase data accuracy.

Nortek Aquadopp Current Profilers

Nortek Aquadopp Current Profiler

The Aquadopp Current Profiler uses 3 acoustic beams slanted at 25 degrees to measure the current profile. The internal tilt and compass sensors measure the direction of the current and the high resolution pressure sensor measures depth. If the system is fixed mounted, the pressure sensor can measure the tidal elevation.

Nortek Aquadopp HR Current Profiler

The HR Aquadopp Current Profiler measures the phase shift between two or more acoustic pulses. The instrument transmits a pulse and then records an echo to measure the velocity along each of the acoustic beams. When a

Above: The extended canister of the Nortek Aquadopp (right) contains a double battery pack for longer autonomous deployments. The housing is either made of titanium (for deep water deployments) or plastic (for intermediate water deployments).

Above: Aquadopp Current Profilers have various sensor head configurations for different applications.

(Above: various types of RDI ADCP and Nortek Aquadopp Profilers. Click images to enlarge them.)

Acoustic Doppler Current Profilers on the Seafloor

Regional Circulation Moorings

The NEPTUNE Regional Network has four Regional Circulation Moorings (RCM) that measure currents within the axial rift valley of Endeavour Ridge at the regional scale, and gauge the effect of hydrothermal venting on regional currents. Each mooring is comprised of three types of instruments including Acoustic Current Meters, CTDs, and Acoustic Doppler Current Profilers (ADCP). These instruments are fixed to a cable at various depths above the seafloor bottom, and measure the current velocity in 3 dimensions and physical properties such as temperature and salinity. The top of the cable is lifted by a large buoy which keeps the line vertical at all times.