DOCSLIB.ORG

A Self-Contained Acoustic Scintillation Instrument for Path-Averaged

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Self-Contained Acoustic Scintillation Instrument for Path-Averaged 1602 JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY VOLUME 22 A Self-Contained Acoustic Scintillation Instrument for Path-Averaged Measurements of Flow and Turbulence with Application to Hydrothermal Vent and Bottom Boundary Layer Dynamics D. DI IORIO Department of Marine Sciences, University of Georgia, Athens, Georgia D. LEMON AND R. CHAVE ASL Environmental Sciences, Sidney, British Columbia, Canada (Manuscript received 21 June 2004, in final form 17 September 2004) ABSTRACT A self-contained acoustical scintillation instrument is described that has been used to measure flow and turbulence characteristics in two diverse oceanographic settings. This instrument is a battery-operated and internally logging acoustic propagation system that is ideally suited to monitor long-term flow and small- scale effective refractive index fluctuations. When the temperature variability dominates the acoustic scat- tering, as is the case of a hydrothermal vent plume, then a measure of the vertical buoyancy-driven flow, together with the root-mean-square temperature fluctuations, can be obtained. Results for vent structure Hulk of the Main Endeavour vent field of the Juan de Fuca Ridge show that the long-term (71 days) temperature fluctuations, together with the vertical flow, can be used to estimate heat flux density. Mea- surements also show oscillations in the log-amplitude variance that result from plume advection by the ambient tidal currents and demonstrate the need for a long time series measurement. When the turbulent velocity dominates the acoustic scattering, as is the case in some energetic bottom boundary layer flows, then the turbulent kinetic energy dissipation rate is derived, assuming isotropic and homogeneous models. The methodology and results are summarized from an application to the Bosporus Canyon of the Black Sea, to monitor the flow and turbulence associated with Mediterranean seawater inflow. 1. Introduction through an inversion of the detected signals. This, of course, is also the goal of acoustic tomography (Munk Acoustical methods are playing an increasingly im- et al. 1995), but here we are concerned with a related portant role in the measurement of small-scale pro- but somewhat different approach that has applications cesses in the ocean. Most of the applications to date are over shorter paths (100–300 m) with the use of a high based on backscatter sonar in various forms; and the acoustic frequency (307 kHz). We refer to this ap- techniques of Doppler and echo sounder measurement proach as acoustical scintillation. Many reports on of ocean currents, internal waves, surface waves, these developments have appeared in the acoustic and bubble fields, mixing processes, and turbulence, as well oceanographic literature using fixed-bottom-mount as biological phenomena, are in a state of rapid devel- frames that are cabled to shore. Here we describe a opment. An alternative and less well developed tech- self-contained instrument that can be used in diverse nology exploits a bistatic system (transmitter and re- deployments to emphasize its potential for oceano- ceiver separately located) to measure the influence of graphic measurement. the medium on signals traveling along wholly refracted The acoustic scintillation method is sensitive to spa- paths. Properties of the medium are then recovered tial structure (the choice of acoustic frequency and range ensures that the scales within the inertial sub- range of turbulence are sampled), and sampling is car- Corresponding author address: Daniela Di Iorio, Department of Marine Sciences, University of Georgia, 230 Marine Sciences ried out fast enough (10–20 Hz) to obtain adequate Building, Athens, GA 30602. temporal statistics. A crucial requirement of the scin- E-mail: [email protected] tillation method for mean flow measurements is that © 2005 American Meteorological Society Unauthenticated | Downloaded 09/30/21 07:51 AM UTC JTECH1799 OCTOBER 2005 D I I O R I O E T A L . 1603 FIG. 1. (a) Acoustic propagation from two sources and two receivers forming parallel paths and (b) sample amplitude time series showing a time delay ␶ between scintillation events. there is sufficient coherence between the signals de- 1961, 1971). Fluctuations in acoustical signals in the tected at two spatially separated receivers, and, for tur- ocean have long been known, but the application of bulence measurements, that the acoustic scattering re- scintillation analysis methods has been more recent. As mains weak. While recognizing the importance of conceived, for example, by Lee and Waterman (1968) larger-scale phenomena (e.g., internal waves) in many in the determination of the speed of the wind, a single environments, our discussion is primarily concerned transmitter, for example, a distant radio source, is de- with turbulent flows that are a dominant characteristic tected at two locations, such that a radial velocity com- of many environments we have measured. In fact, the ponent of the perturbing medium is orthogonal to the measurement of turbulence is a valuable application of two nearly parallel paths joining the transmitter with the scintillation technique in boundary layer dynamics. the two receivers. Refractive perturbations in the me- The advantage of the acoustical scintillation tech- dium pass through the two paths, creating a correlation nique is that path-averaged properties over a baseline in the detected signals, the time lag of which is inversely several times that of the turbulent eddies being mea- proportional to the wind velocity component. Refrac- sured are obtained. The space–time averaging proper- tive variability will produce the perturbations, but a ties of the scintillation method can be an advantage crucial requirement is that there be sufficient coherence because geophysical turbulence is both patchy and in- between the signals detected at the two locations to termittent. Another advantage of the acoustic method allow for a useful measurement to be made. is that there are no probes that are deployed within the The application of this concept to the ocean was first turbulent flow being measured and, thus, it is well demonstrated in a simple set of measurements that suited for the hydrothermal vent application described were acquired with a sound source and pair of hydro- here. phones towed through the water (Clifford and Farmer This paper reports the design and results of a self- 1983; Farmer and Clifford 1986). Moreover, in many contained in situ acoustic scintillation instrument that interesting coastal environments it is possible to fix the was used in two different oceanographic environments. source-and-receiver system to the seafloor so as to pro- The measurement concept and theoretical background vide path stability, but this is not essential and will be describing acoustic propagation is described next in sec- shown with the system described in this paper. The tion 2. The design of the instrument is detailed in sec- application of space–time coherence of the fluctuating tion 3. Section 4 describes the results from a deploy- field distinguishes this approach from most other inver- ment at the Main Endeavour vent field of the Juan de sions of propagation data. Analysis of these signals can Fuca Ridge, and section 5 describes the results from a provide information on the path-averaged current that deployment in the bottom boundary layer of Mediter- is resolved perpendicular to the path and turbulent re- ranean flow through the Bosporus Strait. fractive index intensity and related phenomena. Our survey includes the slowly varying properties, in addi- 2. Measurement concept and theory tion to the fluctuating properties, and is illustrated with results acquired in two very different environments. The concept of acoustic scintillation analysis has its In its simplest configuration (Fig. 1a), two sources origin in studies of wave (optical, radio, or acoustic) transmit an acoustic pulse and are received at two re- propagation through a turbulent atmosphere (Tatarskii ceivers. Both transducers are perpendicular to the Unauthenticated | Downloaded 09/30/21 07:51 AM UTC 1604 JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY VOLUME 22 ␬ ϭ 2 ϩ 2 1/2 acoustic path and aligned with the direction of the main index wavenumber [ (Kx Kz) ] (Tatarskii 1971; flow being measured. Effective refractive index pertur- Clifford 1971; Farmer et al. 1987). Assuming isotropic bations passing through the parallel paths create fluc- and homogeneous turbulence in the plane perpendicu- tuating signals, the time-lagged cross correlation of lar to the direction of acoustic propagation, the log- which can be solved to determine the flow speed. The amplitude cross-correlation function for two parallel parallel path configuration is easy to use, and path- paths is dependent weighting is essentially uniform. L ϱ More generally, we consider the Helmholtz equation ͑ ␶͒ ϭ ␲2 2͵ ͵ ␬␬⌽ ͑␬͒ C␹ rx, 4 k dy d eff for wave propagation in a moving random medium, 0 0 ١p͑r͒ ␬2y͑L Ϫ y͒ · u ͒ ͑ ͪ ϩ 2͑ ͒ 2 ͑ ͒ ϭϪ 2͑ ͒ ͑ ͒ ϫ ͑␬| Ϫ ␶|͒ 2ͩ ͒ ͑ 2ٌ p r n r k p r 2ikn r , 1 J0 rx U sin , 4 co 2kL ⌽ where p(r) is the acoustic pressure field, n(r)isthe where k is the acoustic wavenumber, eff is the three- refractive index of the medium resulting from sound dimensional spectrum of the effective refractive index ϭ speed changes from temperature and salinity, k is the fluctuations evaluated at Ky 0, L is the acoustic acoustic wavenumber, and c␱ is the mean sound speed; propagation distance, and U is the current velocity per- 2 2 u/co is considered to be first order, and orders of u /c pendicular to the propagation direction, but parallel to have been neglected. This equation is a simplified form the hydrophone separation rx. Diffraction effects are of the full linearized sound pressure equation that is described by the sin2 term. obtained by Ostachev (1994), because we neglect gra- This equation shows that the mean current speed (U) dients of oceanographic properties.
Load more

Recommended publications
  • Instrumentation for Monitoring Around Marine Renewable Energy Converters: Workshop Final Report
    PNNL-23100 Prepared for the U.S. Department of Energy under Contract DE-AC05-76RL01830 Instrumentation for Monitoring around Marine Renewable Energy Converters: Workshop Final Report B Polagye A Copping R Suryan S Kramer J Brown-Saracino C Smith January 2014 PNNL-23100 Instrumentation for Monitoring around Marine Renewable Energy Converters: Workshop Final Report B Polagye1 A Copping R Suryan2 S Kramer3 J Brown-Saracino4 C Smith4 January 2014 Prepared for the U.S. Department of Energy under Contract DE-AC05-76RL01830 Pacific Northwest National Laboratory Richland, Washington 99352 1 University of Washington, Northwest National Marine Renewable Energy Center, Seattle, Washington 2 Oregon State University, Newport, Oregon 3 HT Harvey and Associates, Arcata, California 4 US Department of Energy, Wind and Waterpower Technologies Office, Washington, DC Recommended citation: Polagye, B., A. Copping, R. Suryan, S. Kramer, J. Brown-Saracino, and C. Smith. 2014. Instrumentation for Monitoring Around Marine Renewable Energy Converters: Workshop Final Report. PNNL-23110 Pacific Northwest National Laboratory, Seattle, Washington. Summary As the marine energy industry explores the potential for generating significant power from waves and tidal currents, there is a need to ensure that energy converters do not cause harm to the marine environment, including marine animals that may interact with these new technologies in their native habitats. The challenge of deploying, operating, and maintaining marine energy converters in the ocean is coupled with the difficulty of monitoring for potentially deleterious outcomes between the converters, anchors, mooring lines, power cables and other gear, and marine mammals, sea turtles, fish, and seabirds. To better understand the state of instrumentation and capabilities for monitoring around marine energy converters, the U.S.
    [Show full text]
  • Prestudy on Sonar Transponder
    Prestudy on Sonar Transponder Dag Lindahl & Leigh Boyd, Avalon Innovation September 2018, Västerås, Sweden External consultant: Avalon Innovation AB Dag Lindahl, Business Manager Project North, +4670 454 37 08, [email protected] Leigh Boyd, System Development Engineer +4670 454 43 44, [email protected] Avalon Innovation AB, Skivfilargränd 2 721 30 Västerås, Sweden Org nr: 556546-4525, www.avaloninnovation.com Contractor Marine Center, Municipality of Simrishamn Coordination and editing Vesa Tschernij, Marine Center MARELITT Baltic Lead Partner Municipality of Simrishamn Marine Center, 272 80 Simrishamn, Sweden Contact Vesa Tschernij, Project Leader [email protected] +4673-433 82 87 www.marelittbaltic.eu The project is co-financed by the Interreg Baltic Sea Region Programme 2014-2020. The information and views set out in this report are those of the authors only and do not reflect the official opinion of the INTERREG BSR Programme, nor do they commit the Programme in any way. Cover photo: P-Dyk Table of Contents Introduction 1 Background 3 Sonars and fish finders 3 Active - Beacons 4 Active - Transponders 5 Passive - Reflectors 5 Transmitter power and frequencies 6 Chirp vs. Ping 7 Beam characteristics 7 Propagation in water 7 Returned signal from underwater targets 8 Receiver sensitivity 9 Link- and power budget calculations 9 Transmitter output power 9 Transmitter output efficiency 10 Transmitter lobe directivity and spreading losses. 10 Propagation loss through water to target (and back) 10 Noise 10 Ideas 11 Resonators as energy storage elements or harvesters 11 Conclusions 12 Recommendations for further work 13 Ghost Net Hotline 13 Transponders - to help retrieve nets lost in the future 13 Improving the Sonar Data at the source 14 Computerized Post Processing 14 Map/Database 15 Dispatching algorithm 15 Remotely Operated Vehicles 16 References 17 Introduction Avalon Innovation has been asked to investigate the potential for making a sonar responder, driven by the energy in the sonar pulse.
    [Show full text]
  • A Review and Inventory of Fixed Autonomous Recorders for Passive Acoustic Monitoring of Marine Mammals Renata S
    Aquatic Mammals 2013, 39(1), 23-53, DOI 10.1578/AM.39.1.2013.23 A Review and Inventory of Fixed Autonomous Recorders for Passive Acoustic Monitoring of Marine Mammals Renata S. Sousa-Lima,1, 2, 5 Thomas F. Norris,3 Julie N. Oswald,3, 4 and Deborah P. Fernandes5 1Bioacoustics Research Program, Cornell Lab of Ornithology, 159 Sapsucker Woods Road, Ithaca, NY 14850, USA E-mail: [email protected] 2Programa de Pós-Graduação em Ecologia, Conservação e Manejo de Vida Silvestre, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, Belo Horizonte, MG 31270, Brasil 3Bio-Waves, Inc., 144 W. D Street, Suite #205, Encinitas, CA 92024, USA 4Oceanwide Science Institute, PO Box 61692, Honolulu, HI 96839, USA 5Laboratório de Bioacústica e Programa de Pós Graduação em Psicobiologia, Departamento de Fisiologia, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Caixa Postal 1511, Campus Universitário, Natal, RN 59078-970, Brasil Abstract sounds produced by marine mammals to more effectively study them. Fixed autonomous acoustic recording devices In 1880, Pierre and Jacques Curie (1880a, (autonomous recorders [ARs]) are defined as 1880b) discovered that when mechanical pressure any electronic recording system that acquires was exerted on a quartz crystal, an electric poten- and stores acoustic data internally (i.e., without a tial is produced. This finding enabled the devel- cable or radio link to transmit data to a receiving opment of the first device capable of listening to station), is deployed semi-permanently underwa- sounds underwater—passive acoustic monitoring ter (via a mooring, buoy, or attached to the sea (PAM), which was utilized during World War I.
    [Show full text]
  • Yet2 – NOAA Buoyless Gear Location Marking Pivot Report
    NOAA Topic Specific Scouting yet2 Buoyless Gear Location Marking Project Pivot Report October 21, 2020 Contents • Executive Summary • Description of Targets • Appendices 2 Executive Summary Project Objective • Identification of technologies/companies that have the potential/expertise to develop and commercialize a Buoyless Underwater Object Location Marking System. • Assessment of the most promising potential solution providers and interviews with potential partners. Results to Date • yet2 has sent 41 relevant targets to NOAA to be reviewed. o Looked at Ropeless Fishing Systems, commercially available technologies/systems and novel academic research of Underwater Communication, Positioning, and Networking systems, and its individual components. o Reviewed acoustic, optical, and electromagnetic systems, novel methods, modems, and power transfer techniques. • NOAA reviewed and provided feedback on all 41 targets and has identified 39 companies with relevant expertise developing and commercializing underwater Communication & Positioning Systems. • Important results to date: o NOAA contacted and invited all in scope and relevant targets to the Ropeless Consortium Annual meeting. o yet2 gained insights on the state of the art of Underwater Communication And Location Systems to inform NOAA, who will use this information to work on the specifications for a Bouyless Gear Location Marking System. 3 General Observations and Next Steps General Observations Pricing While there are many companies with capabilities and existing products around NOAA’s desired system, most are not within the desired cost range. • A traditional system for monitoring high-value assets such as underwater autonomous vehicles, cost upwards of $15,000. • Some researchers have built low cost devices ($100-1000) from raw materials, but it does not appear that these devices are being manufactured on a commercial scale.
    [Show full text]
  • Research Article Nonstationary System Analysis Methods for Underwater Acoustic Communications
    Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2011, Article ID 807472, 14 pages doi:10.1155/2011/807472 Research Article Nonstationary System Analysis Methods for Underwater Acoustic Communications Nicolas F. Josso,1 Jun Jason Zhang,2 Antonia Papandreou-Suppappola,2 Cornel Ioana,1 and Tolga M. Duman2 1 GIPSA-Lab/DIS, Grenoble Institute of Technology (GIT), 38402 Grenoble, France 2 School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, AZ 85287-9309, USA Correspondence should be addressed to Antonia Papandreou-Suppappola, [email protected] Received 3 August 2010; Accepted 26 December 2010 Academic Editor: Antonio Napolitano Copyright © 2011 Nicolas F. Josso et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The underwater environment can be considered a system with time-varying impulse response, causing time-dependent spectral changes to a transmitted acoustic signal. This is the result of the interaction of the signal with the water column and ocean boundaries or the presence of fast moving object scatterers in the ocean. In underwater acoustic communications using medium- to-high frequencies (0.3–20 kHz), the nonstationary transformation on the transmitted signals can be modeled as multiple time- delay and Doppler-scaling paths. When estimating the channel, a higher processing performance is thus expected if the techniques used employ a matched channel model compared to those that only compensate for wideband effects. Following a matched linear time-varying wideband system representation, we propose two different methods for estimating the underwater acoustic communication environment.
    [Show full text]
  • 3 Affected Environment and Environmental Consequences
    Atlantic Fleet Training and Testing Draft EIS/OEIS June 2017 Draft Environmental Impact Statement/Overseas Environmental Impact Statement Atlantic Fleet Training and Testing TABLE OF CONTENTS 3 AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES ....................................... 3.0-1 3.0 Introduction ........................................................................................................... 3.0-1 3.0.1 Navy Compiled and Generated Data .................................................................. 3.0-1 3.0.1.1 Marine Species Monitoring and Research Programs ......................... 3.0-1 3.0.1.2 Marine Species Density Database....................................................... 3.0-2 3.0.1.3 Developing Acoustic and Explosive Criteria and Thresholds .............. 3.0-3 3.0.1.4 Aquatic Habitats Database ................................................................. 3.0-4 3.0.2 Ecological Characterization of the Study Area .................................................... 3.0-4 3.0.2.1 Biogeographic Classifications.............................................................. 3.0-4 3.0.2.2 Bathymetry ....................................................................................... 3.0-12 3.0.2.3 Currents, Circulation Patterns, and Water Masses .......................... 3.0-14 3.0.2.4 Ocean Fronts ..................................................................................... 3.0-27 3.0.2.5 Abiotic Substrate .............................................................................. 3.0-27
    [Show full text]
  • Long-Term Autonomous Hydrophones for Large-Scale Hydroacoustic Monitoring of the Oceans Jean-François D’Eu, Jean-Yves Royer, Julie Perrot
    Long-term autonomous hydrophones for large-scale hydroacoustic monitoring of the oceans Jean-François d’Eu, Jean-Yves Royer, Julie Perrot To cite this version: Jean-François d’Eu, Jean-Yves Royer, Julie Perrot. Long-term autonomous hydrophones for large- scale hydroacoustic monitoring of the oceans. Yeosu 2012, May 2012, Yeosu, North Korea. pp.1-6, 10.1109/OCEANS-Yeosu.2012.6263519. insu-00817948 HAL Id: insu-00817948 https://hal-insu.archives-ouvertes.fr/insu-00817948 Submitted on 22 May 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Long-term autonomous hydrophones for large-scale hydroacoustic monitoring of the oceans Jean-François D’Eu, Jean-Yves Royer, Julie Perrot Laboratoire Domaines Océaniques CNRS and University of Brest Plouzané, France [email protected] Abstract—We have developed a set of long-term autonomous hydrophones dedicated to long-term monitoring of low-frequency A. Monitoring ocean seismicity at a broad scale sounds in the ocean (<120Hz). Deploying arrays of such Seismicity in the ocean is usually recorded with the help of hydrophones (at least 4 instruments) proves a very efficient seismometers, such as Ocean Bottom Seismometers (OBS), approach to monitor acoustic events of geological origin placed in the proximity of active areas.
    [Show full text]
  • Passive Acoustic Monitoring Projects and Sound Sources in the Gulf of Mexico
    OCS Study BOEM 2020-009 Literature Synthesis: Passive Acoustic Monitoring Projects and Sound Sources in the Gulf of Mexico U.S. Department of the Interior Bureau of Ocean Energy Management New Orleans Office OCS Study BOEM 2020-009 Literature Synthesis: Passive Acoustic Monitoring Projects and Sounds Sources in the Gulf of Mexico Authors Jennifer N. Latusek-Nabholz Amy D. Whitt Dagmar Fertl Dennis R. Gallien Anwar A. Khan Natalia Sidorovskaia Prepared under BOEM Contract M17PC00001 by HDR, Inc. 300 N. Madison Street Athens, Georgia 35611 Published by U.S. Department of the Interior New Orleans, LA Bureau of Ocean Energy Management January 2020 New Orleans Office DISCLAIMER Study concept, oversight, and funding were provided by the US Department of the Interior, Bureau of Ocean Energy Management, Environmental Studies Program, Washington, DC, under Contract Number M17PC00001, Task Order No. M17PD00011. This report has been technically reviewed by BOEM, and it has been approved for publication. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the opinions or policies of the U.S. government, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. REPORT AVAILABILITY To download a PDF file of this report, go to the US Department of the Interior, Bureau of Ocean Energy Management Data and Information Systems webpage (http://www.boem.gov/Environmental-Studies- EnvData/), click on the link for the Environmental Studies Program Information System (ESPIS), and search on 2020-009. The report is also available at the National Technical Reports Library at https://ntrl.ntis.gov/NTRL/.
    [Show full text]
  • DELIVERABLE 2.1 Monitoring Plans for Noise, Electromagnetic Fields and Seabed Integrity
    WAVE ENERGY IN SOUTHERN EUROPE | Deliverable 2.1. Monitoring plans for Noise, Electromagnetic Fields and Seabed Integrity DELIVERABLE 2.1 Monitoring plans for Noise, Electromagnetic Fields and Seabed Integrity 1 WAVE ENERGY IN SOUTHERN EUROPE | Deliverable 2.1. Monitoring plans for Noise, Electromagnetic Fields and Seabed Integrity 2 WAVE ENERGY IN SOUTHERN EUROPE | Deliverable 2.1. Monitoring plans for Noise, Electromagnetic Fields and Seabed Integrity WP 2 Environmental Monitoring Deliverable 2.1 Monitoring plans for Noise, Electromagnetic Fields and Seabed Integrity PROJECT COORDINATOR AZTI TASK LEADER AZTI AUTHORS Pedro Vinagre, WavEC Erica Cruz, WavEC Paulo Chainho, WavEC Pablo Ruiz, CTN Ivan Felis, CTN Iñigo Muxika, AZTI Juan Bald, AZTI SUBMISSION DATE 28 | February| 2019 CITATION Vinagre P.A., Cruz E., Chainho P., Ruiz P., Felis I., Muxika I., Bald J., 2019. Deliverable 2.1 Monitoring plans for Noise, Electromagnetic Fields and Seabed Integrity. Corporate deliverable of the Wave Energy in the Southern Europe (WESE) Project funded by the European Commission. Agreement number EASME/EMFF/2017/1.2.1.1/02/SI2.787640. 60 pp. 3 WAVE ENERGY IN SOUTHERN EUROPE | Deliverable 2.1. Monitoring plans for Noise, Electromagnetic Fields and Seabed Integrity WESE Wave Energy in the Southern Europe D2.1 Monitoring plans for Noise, Electromagnetic Fields and Seabed Integrity 4 WAVE ENERGY IN SOUTHERN EUROPE | Deliverable 2.1. Monitoring plans for Noise, Electromagnetic Fields and Seabed Integrity CONTENTS 1. WESE PROJECT SYNOPSIS ......................................................................................................................
    [Show full text]
  • Report of the NABOS/CABOS 2010-2011 Arctic Ocean Mooring Recovery
    IARC Technical Report # 8 Report of the NABOS/CABOS 2010-2011 Arctic Ocean mooring recovery Summary of NABOS/CABOS mooring operations With support from: NSF 1 TABLE OF CONTENTS PREFACE ( I.Polyalov )…….………………………………..………………………..….………....... 5 I. NABOS MOORING RECOVERY DURING ICE CRUISE 2010, R/V LANCE …………….……… 7 I.1. INTRODUCTION (I.Polyakov)………………………………………..…………………………… 8 I.2. RESEARCH VESSEL …………..………………………………………………………….......... 8 I.3. OUTLINE FOR MOORING OPERATIONS ……………..……….................................................. 9 I.3.1. Attempt to recover SAMS mooring (I. Waddington) ....………………………………………….… 9 I.3.2. Recovery of M4c mooring (I. Waddington)……………………………………………………. 11 I.3.3. Downloading M4c mooring data (I. Waddington)………………………………………………………... 14 I.3.4. Preliminary look at M4c mooring data …............................................................................. 14 I.4. ACKNOWLEDGEMENTS ……………..………........................................................................... 16 II. NABOS MOORINGS RECOVERY DURING ARK-XXVI/3 CRUISE 2011, R/V POLARSTERN 19 II.1. INTRODUCTION (I.Polyakov)……………………………………..…..………………………… 20 II.2. RESEARCH VESSEL ………..……………………………………..…………………….......... 21 II.3. OUTLINE FOR MOORING OPERATIONS …………..………..................................................... 21 II.3.1. M11a mooring ....………………………………………………..…………………………….… 21 II.3.1.1. Recovery of M11a mooring (I. Waddington)……………………….…………………… 21 II.3.1.2. Preliminary look at M11a mooring data ….............................................................. 24
    [Show full text]
  • Damocle Ss D8.2-06
    Project no. 018509 DAMOCLES Developing Arctic Modelling and Observing Capabilities for Long-term Environment Studies Instrument: Integrated Project Thematic Priority: 6.3 “Global Change and Ecosystems” D8.2-06 - Results from the Fram Strait acoustic tomography experiment and system evaluation Due date of deliverable: 30/05/2010 Actual submission date: 20/06/2010 Used Person/months: 9.75 Start date of project: 1 December 2005 Duration: 54 months Organisation name of lead contractor for this deliverable: NERSC Project co-funded by the European Commission within the Sixth Framework Programme (2002-2006) Dissemination Level PU Public PP Restricted to other programme participants (including the Commission Services) X RE Restricted to a group specified by the consortium (including the Commission Services) CO Confidential, only for members of the consortium (including the Commission Services) D8.2-06 - Results from the Fram Strait acoustic tomography experiment and system evaluation TITLE: D8.2-06 - Results from the Fram Strait acoustic REPORT IDENTIFICATION tomography experiment and system evaluation DAMOCLES Deliverable D8.2 CLIENT : CONTRACT DAMOCLES Contract Instrument: Integrated Project Grant agreement no.: 018509 Thematic Priority: 6.3 “Global Change and Ecosystems” CLIENT REFERENCE AVAILABILITY Open report within the DAMOCLES consortium. INVESTIGATORS AUTHORISATION Svein Arild Haugen, NERSC, Norway Hanne Sagen, NERSC, Norway Stein Sandven, NERSC, Norway Bergen, 20 June 2010 Matthew Dzieciuch, SIO, USA Peter Worcester, SIO, USA Emmanuel
    [Show full text]
  • A Vector Sensor-Based Acoustic Characterization System for Marine Renewable Energy
    Journal of Marine Science and Engineering Article A Vector Sensor-Based Acoustic Characterization System for Marine Renewable Energy Kaustubha Raghukumar *, Grace Chang , Frank Spada and Craig Jones Integral Consulting Inc, Santa Cruz, CA 95062, USA; [email protected] (G.C.); [email protected] (F.S.); [email protected] (C.J.) * Correspondence: [email protected]; Tel.: +1-831 466 9630 Received: 9 January 2020; Accepted: 6 March 2020; Published: 10 March 2020 Abstract: NoiseSpotter is a passive acoustic monitoring system that characterizes, classifies, and geo-locates anthropogenic and natural sounds in near real time. It was developed with the primary goal of supporting the evaluation of potential acoustic effects of offshore renewable energy projects. The system consists of a compact array of three acoustic vector sensors, which measures acoustic pressure and the three-dimensional particle velocity vector associated with the propagation of an acoustic wave, thereby inherently providing bearing information to an underwater source of sound. By utilizing an array of three vector sensors, the application of beamforming techniques can provide sound source localization, allowing for characterization of the acoustic signature of specific underwater acoustic sources. Here, performance characteristics of the system are presented, using data from controlled acoustic transmissions in a quiet environment and ambient noise measurements in an energetic tidal channel in the presence of non-acoustic flow noise. Data quality is demonstrated by the ability to reduce non-acoustic flow noise contamination, while system utility is shown by the ability to characterize and localize sources of sound in the underwater environment. Keywords: marine renewable energy; acoustics; environmental characterization 1.
    [Show full text]