Seminar: Buoyancy controlled float swarms for distributed sensing in coastal waterways

Trevor Harrison
National Science Foundation Fellow
Department of Mechanical Engineering
University of Washington

Abstract
Buoyancy-controlled underwater floats have produced a wealth of in situ observational data from the open ocean. When deployed in large numbers, or ‘swarms’, floats offer a unique capacity to simultaneously map, in three-dimensions, environmental variables, such as currents, temperatures, and dissolved oxygen. This sensing paradigm is equally relevant in coastal waterways, yet remains underutilized due to economic and technical limitations of existing platforms. To that end, we have developed the microFloat, a buoyancy-controlled float designed specifically for the strong currents and density gradients observed in coastal systems. This talk will provide an overview of microFloat design, the field tests undertaken to benchmark depth control and underwater localization, and a field test in Agate Pass, WA comparing water velocity estimates from a swarm of twenty microFloats to station-keeping and drifting acoustic Doppler current profiler measurements, as well as additional temperature mapping provided by the float swarm.

About the speaker
Trevor Harrison is a newly minted Doctor, having just received his PhD in the department of Mechanical Engineering at the University of Washington. For the past six years, he’s been working on the microFloats, which you’ll be hearing about today. He received his Bachelor of Science in Physics at the College of William and Mary, and spent two years working at Woods Hole Oceanographic Institution as a Research Assistant, which inspired his interest in ocean instrumentation. In fall of 2013, he joined the Marine Renewable Energy Lab headed by Dr. Brian Polagye, initially working on a stereo optical and infrared camera system for bird and bat observations around offshore wind turbines. In 2014, he received an NSF Graduate Research Fellowship, which supported the shift to developing the microFloat system. At the end of this quarter, he’ll be headed to Applied Physics Laboratory at UW for a year-long post-doc.