HIGH RESOLUTION COHERENT ACOUSTIC DOPPLER CURRENT PROFILER

THIS RESEARCH AND DEVELOPMENT PROJECT WILL STUDY THE FEASIBILITY OF DEVELOPING A HIGH RESOLUTION COHERENT ACOUSTIC DOPPLER CURRENT PROFILER (HRCADCP) SUITABLE FOR MEASURING PROFILES OF 3-AXES VELOCITY OVER SHORT RANGES WITH HIGH ACCURACY, SPATIAL RESOLUTION AND SAMPLING RATE. CAPABILITY FOR MEASURING CURRENT PROFILES FROM THE OCEAN'S SURFACE TO A 1-METER DEPTH WITH VELOCITY ACCURACY OF ORDER A FEW MM/S, SPATIAL RESOLUTION OF A FEW MM AND SAMPLING RATES OF ABOUT 10 HZ WILL BE SOUGHT. THE PROPOSED APPROACH USES A BISTATIC PULSECOHERENT ACOUSTIC DOPPLER SYSTEM WHICH UTILIZES AN ARRAY OF FOUR RECEIVER ASSEMBLIES TO MEASURE DOPPLER FREQUENCIES FROM ECHOES SCATTERED FROM THE WATERMASS VOLUME ENSONIFIED BY A SINGLE TRANSMIT TRANSDUCER AT THE CENTER OF THE ARRAY. THE PRIMARY OBJECTIVES OF PHASE I ARE TO ANALITICALLY DEFINE AND QUANTIFY THE SOURCES OF ERROR IN THE MEASURMENT PROCESS, TO EXPLORE THE RELATIVE MERITS AND PERFORM-ANCE OF ALTERNATIVE SYSTEM GEOMETRIES AND SIGNAL PROCESSING SCHEMES, AND TO CONDUCT AN EXPERIMENT TO EVALUATE THE PRACTICAL FEASIBILITY AND PERFORMANCE OF SYSTEM.