UACE: Demonstration of a directional acoustic profiling float powered by ocean thermal energy conversion

• Day: June 16, Monday
    Location / Time: A. TERPSIHORI at 18:20-18:40
• Last minutes changes: -
• Session: 03. Advances in acoustic measurement systems: Technologies and applications
  Organiser(s): Alessandra Tesei, Matthew Schinault, Purnima Ratilal
  Chairperson(s): Matthew Schinault
• Lecture: Demonstration of a directional acoustic profiling float powered by ocean thermal energy conversion
  Paper ID: 2184
  Author(s): Kaustubha Raghukumar, Paul Chamberlain, Grace Chang, Yi Chao, Sean Griffin, John Joesph, Mathew Mazzloff, John Ryan
  Presenter: Kaustubha Raghukumar
  Abstract: There is a paucity of acoustic data at full ocean depths, primarily due to the logistical challenges in deploying and recovering traditional acoustic sensing platforms in difficult-to-reach regions of the world’s oceans. To address this challenge, a near real-time, ocean thermal energy conversion-powered, directional acoustic profiling float is being developed that can be navigated using modeled ocean currents. The float battery is recharged by an ocean thermal energy conversion (OTEC) engine and directional acoustic measurements are made using an off-the shelf vector sensor suspended below the float that measures acoustic pressure and particle velocity in the 10 Hz- 3 kHz frequency range. Other data collected include conductivity, temperature and depth data, and float metadata such as float volume and telemetered GPS positions during resurfacing.\n\nWe report on the results of a field trial that was conducted offshore of San Diego, California (USA) where the float was deployed for a period of 24 hours in ~700 m deep water. The float conducted three dives down to 400 m at which it parked. While acoustic measurements were made throughout the deployment, the bulk of the usable acoustic data occurred when the float was parked at depth with all pumps turned off. The transit period through the water column was marked by extensive flow noise. Ambient noise data consisted of wind noise, passing vessels and helicopters transiting overhead, all of which were directionally resolved. The Copernicus ocean model was found to have the best skill in reproducing float trajectories. While in this demonstration the acoustic measurement subsystem was independent of the float subsystem, efforts are ongoing to not only power the acoustic system by the float, but also to integrate processed acoustic products into the telemetry stream. \n
• Corresponding author: Dr Kaustubha Raghukumar
  Affiliation: Integral Consulting Inc.
  Country: United States