In this Phase I SBIR proposal, RD Instruments proposes to demonstrate the feasibility of developing an Acoustic Doppler Current Profiler (ADCP) with twice the depth range of existing instruments. The proposed instrument will be able to measure the velocity of water masses to a depth of 1500m. In order for scientists to make realistic estimates of oceanographic currents, velocity measurements to a depth of at least 1200m are essential. Present ADCP capabilities are limited to about 700m. Velocity measurements of water masses requires a narrow acoustic beam width and extremely precise measurement of acoustic signals reflected from small particles in the water in order to locate those particles. In addition, measurement of phase shifts in the return acoustic beam indicate the velocity of those particles, and hence the velocity of the water mass.
