What does the acronym ADCP stand for in oceanography?

In oceanography, ADCP stands for Acoustic Doppler Current Profiler. It is a sonar-like instrument that measures water-current speed and direction through the Doppler shift of sound scattered back from particles suspended in the water.

An ADCP sends acoustic pulses through one or more beams and times their echoes to estimate distance. The frequency change in each echo reveals the water’s velocity along that beam. Combining measurements from multiple angled beams allows the instrument to calculate current components and build a profile through the water column.

ADCPs are used from ships, moorings, riverboats, bridges, seabeds, and underwater vehicles. Depending on its placement, an instrument may look upward, downward, or sideways. A ship-mounted ADCP can also use bottom tracking to separate the vessel’s motion from the surrounding current.

A common mix-up is confusing an ADCP with a Doppler velocity log, or DVL. Both use Doppler acoustics, but an ADCP primarily profiles water motion, while a DVL commonly measures a vehicle’s motion relative to the seafloor or water.