LIttoral Drifter for Sensing Properties of Shallow Waters and Sediments

Scripps Institute of Oceanography (SIO) with ONR support has developed the methodology to utilize acoustic sensors suitable for incorporation in autonomous drifting sampling instruments for measuring vertical current structure in shallow waters, water depth, bottom sediment characteristics, and acoustically active water column properties. Clearwater Instrumentation designs and manufactures satellite-linked, low-cost, long-lived, self-locating (GPS), autonomous drifters incorporating a variety of environmental sensors. CCD designs miniature GPS sensing systems, wave spectrum analyzers and has expertise in acoustic bottom characterization. SIO will assist CCD and Clearwater by transferring the knowledge necessary to incorporate active acoustic current-profiling and bottom characterizing sensors and measurement systems into a small low-cost autonomous expendable instrument, and by assisting in the development of algorithms to determine wave characteristics from GPS data. This expendable environmental sensor system is intended for observing and characterizing littoral conditions, including rivers, estuaries and lagoons. BENEFITS: This research and development project will lead to a low-cost current-profiling, autonomous drifter capable of measuring new parameters that increase the value of surface current measurements already available from these instruments: water depth, bottom sediment characteristics, wave height and biologically induced sound targets. New environmental parameters to be measured have potential commercial application in studies of coastal pollution monitoring and control, verification of hydrodynamic models of littoral/shelf interactions and survey of remote, inaccessible shallow water domains.