Ocean flow measurement using an autonomous underwater vehicle

In this paper, we discuss making flow measurements in a shallow-water ocean environment using Florida Atlantic University's 2.2 m long autonomous underwater vehicle (AUV). An AUV has the advantage over tethered vehicles in that its self motion is not coupled to the motion of the sea surface and that of a mother ship, and it can potentially operate in stormy conditions. Two high-wavenumber shear probes and a Pitot tube, housed in a pressure-vessel mounted on the nose of the AUV, allow measurements, in the dissipation range, of all three components of velocity. Salinity, temperature, mean velocity gradients and possible body vibrations are monitored using auxiliary local probes. The AUV allows surveying 3-5 mile square regions at a speed of 3-4 knots. The influence of the self motion of the AUV on the flow measurements is discussed.