Assessment of an ADCP???s capabilities in laboratory conditions

A Nortek Aquadopp current profiler was tested at the University of Strathclyde´s Kelvin Hydrodynamics Laboratory. To evaluate both the accuracy and precision of the instrument, it was towed on a carriage at a range of speeds up to 3.5ms^-1. The effect of the spatial resolution and range parameter settings on these uncertainties has also been studied. Subsequent tests were performed to assess the disturbance characterisation and tracking capabilities of the instrument. These tests took place under regular wave conditions with the carriage held stationary. The precision of the instrument was found to be unaffected by tow speed, while accuracy decreased. Disturbance profiles similar to those predicted from theory were observed and tracked over consecutive time steps, despite the induced currents from the waves being low in magnitude. The instrument underestimated the peak values of these horizontal velocities, however, but this should be expected considering the instrument´s principles of operation. Measurements of wavelength and phase velocity, both constant with respect to time, were found to be more accurate.