RD Instruments will undertake an SBIR Phase II proposal to continue development and commercialization of a phased array acoustic Doppler current profiler (PAADCP). This company has pioneered the use of acoustic Doppler techniques for a variety of ocean science and applied oceanographic applications. The project will reduce the size and weight of presently available instruments and make them more versatile by developing a single phased array to replace the four independent piston transducers that are now required. A 38 kHz phased array transducer will have a significantly smaller diameter and be lighter in weight than the four 75 kHz transducers now used. A fifth beam can also be formed to add a new capability of measuring vertical velocities as well as lateral velocities. Its smaller flat shape will make it easier to mount in ships and elsewhere. Additionally, it is anticipated that it will have nearly double the profiling range of present instruments. To achieve the objectives, several tasks will be undertaken. These will include a design trade-off study to validate theoretical models developed during Phase I concerning the ceramic geometries of the transducer and their resulting beam patterns. Broadband technology options will be examined for implementation. The 38.5 kHz ceramic transducers will be designed and packaged along with the electronics and data management system. Signal processing algorithms will be developed. There will also be an extensive testing program in laboratory tanks and at sea in collaboration with academic ocean scientists. If successful, this new PAADCP could be the next generation acoustic profiling system and will have broad applications on U.S. and foreign research vessels and in offshore commercial applications as well.
