AN AUTOMATED AND SUBMERSIBLE OPTICAL SENSOR FOR VERY-NEAR BOTTOM MOMENTUM CHARACTERIZATION

THIS PHASE I PROJECT WILL DEVELOP AN AUTOMATED AND SUBMERSIBLE SENSOR THAT MEASURES VERY NEAR BOTTOM FLUID FLOWS, SUSPENDED PARTICULATE SIZES AND CONCENTRATIONS, AND MOMENTUM EXCHANGES IN THE COASTAL OCEAN ENVIRONMENT. COMPUTER-AIDED SPECKLE INTERFEROMETRY WILL BE USED TO DEDUCE A TWO-DIMENSIONAL FLOW FROM SPECKLE PATTERNS OF NATURAL PARTICULATES. PARTICULATES ARE MEASURED THROUGH LONG-DISTANCE MICROSCOPY. THE SENSOR HAS A TEMPORAL RESOLUTION OF 33 MS OVER SUB-MILLIMETER SCALES. IT PROVIDES SEA TRUTH DATA ON CRITICAL SUBSURFACE OCEAN PROCESSES THAT CANNOT BE MEASURED REMOTELY. THE SYSTEM INCLUDES A LASER, MICROPROCESSOR, VIDEO CAMERAS, OPTICS, AND A RECORDER. POWER REQUIRMENTS ARE LOW--THE SENSOR OPERATES WHILE SUBMERGED FOR SEVERAL MONTHS. POWER IS CONSERVED WITH NEURAL NETWORKS--THE SENSOR SENSES ENVIRONMENTAL CHANGES, AND SAMPLES ACCORDINGLY. BIOFOULING AND CORROSION ARE ADDRESSED THROUGH SAMPLING MINIMIZATION, SHUTTERS, AND MATERIALS SUCH AS COPPER ALLOYS. FEASIBILITY WILL BE VERIFIED THROUGH HARDWARE TESTS. SPECIFICALLY, PHASE I WILL CONSTRUCT A LABORATORY SPECKLE INTERFEROMETER THAT DEDUCES TWO-DIMENSIONAL FLOW FIELDS FROM NATURAL OCEAN PARTICULATE SIDE-SCATTER. BOTH FLOW AND PARTICULATE DATA WILL BE USED TO TRAIN NEURAL NETWORKS THAT RECOGNIZE ENVIRONMENTAL CHANGES. A DETAILED SENSOR DESIGN WILL BE PRODUCED THAT INCLUDE POWER REQUIREMENTS, OPERATIONAL ESTIMATES, AND BIOFOULING AND CORROSION COUNER-MEASURES.