The autonomous profiling vehicle (APV)

The APV is an autonomous vertical profiling free fall instrument composed of: a sensor suite, a data transmission (via radio frequency) system, and a location system (GPS), a buoyancy engine and pressure housing. Conductivity and temperature versus depth data has been collected from the surface to 1000 meters. A minimum of 50 profiles to 1000 meters can be made. In addition to CTD data, calculations are made of vertical fluid velocities based an the differences in the instrument's absolute terminal velocity related to the drag forces, and the measured absolute fall rate dp/dt. The instrument ascent/descent rates are adjustable to provide multi-depth drifter records.<>