Next Generation Acoustic Doppler Current Profilers for REMUS UUVs
Abstract
Next Generation Acoustic Doppler Current Profilers for REMUS UUVs We propose integration of advanced Nortek Signature1000 acoustic Doppler currentprofilers (ADCPs) onto our REMUS 100 unmanned underwater vehicles (UUVs) to enable autonomous targeted observations of small-scale coherent currents and turbulence with unprecedented resolution, accuracy, and coverage.Understanding and prediction of near-surface currents in open-ocean and coastal environments is of utmost importance for naval operations, maritime emergency response, and environmental protection. Currents, associated with sharp changes (fronts) in ocean and estuarine water properties, are particularly poorly understood. They cause immediate operational impacts: Fronts concentrate air bubbles, plankton, and marine debris, thus drastically degrading underwater visibility and impeding acoustic communications. Furthermore, frontal currents themselves pose a real threat to autonomous operations, as they can easily overwhelm the UUVs controls and leado wasting battery resources, hostile detection, and ultimately the loss of vehicles.Investigation of frontal processes has been hindered by the inherent difficulties associated with measuring the 3D structure of strong but extremely localized frontal currents, but recent advances in ocean technology now bring these detailed observations within reach. At least two current ONR Departmental Research Initiatives (DRIs) leverage these advances using state-of-theart autonomous instrumentation. The CALYPSO DRI specifically aims to identify surface-to interior transport structures and pathways. Similarly, the USRS DRI seeks to understand the distribution and characteristics of suspended scatterers (bubbles, sediment, plankton) that enableacoustic and optical remote sensing of dynamic frontal features, but also impedes underwater acoustic navigation and communication. In both DRIs, our APL-UW team uses REMUS 100 UUVs to conduct coordinated targeted autonomous observations of the frontal environments. The REMUS 100s strength lies in their ability to take advanced and versatile in-situ measurements at the core of dynamic features in locations inaccessible with larger vessels. Our vehicles carry state-of-the-art instrumentation suites to measure temperature, salinity, oxygen saturation, and bio-optical parameters. However, the UUVs ability to measure the strong three-dimensional turbulent currents encountered in tidal estuaries and open-ocean frontal convergence zones has been thus far been limited by the lack of modern instrumentation for current profiling a limitation we propose to remedy. This proposal is to equip our two REMUS 100 UUVs with advanced five-beam acoustic Dopplercurrent profilers (ADCPs), which, to our knowledge, have never before been carried by UUVs. This acquisition will dramatically enhance our capacity to observe both coherent and turbulent currents with unprecedented precision, resolution, and coverage. Integration of these next generationADCPs will also allow us to conduct aliasing-free targeted observations of the vertical component of frontal circulation from an underwater vehicle an observational capability that has not been available to-date.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 20, 2020
- Source ID
- N000142012459
Entities
People
- Andrey Y. Shcherbina
Organizations
- Office of Naval Research
- United States Navy
- University of Washington