ADCPvel

ADCPvel is a term used to describe the velocity data produced by Acoustic Doppler Current Profilers (ADCPs). It usually refers to the vertical profile of horizontal current velocity (u and v) with depth and time, though some datasets also include vertical velocity estimates or derived quantities.

ADCPs measure acoustic Doppler shifts along multiple beams; the raw measurements are converted to velocity components in instrument coordinates and then rotated to earth or grid coordinates using the instrument attitude and orientation data. The resulting ADCPvel data are typically organized as depth bins for each sampling interval, with timestamps and quality flags.

Data formats vary; common outputs include netCDF, HDF5, or vendor-specific binary and ASCII files. Processing may be performed with software such as MATLAB, Python (e.g., xarray, pyadcp), R, or specialized tools; workflows often include beam-to-earth coordinate transformation, spurious velocity removal, tilt/heading corrections, and bin averaging.

Applications include coastal and estuarine hydrodynamics, upwelling studies, river discharge estimation, and exchange flows; ADCPvel values are frequently used in tidal analyses and numerical model validation.

Limitations include instrument tilt, vessel motion, low signal-to-noise in shallow waters, partial beam interference, and the need for quality control. Transparent documentation of processing steps and metadata is essential for reproducibility.

See also: Acoustic Doppler velocimeter, Acoustic Doppler Current Profiler, netCDF, velocity profiling.