Underwater, Physical and Engineering Acoustics

John S. Allen III

Department of Mechanical EngineeringUniversity of Hawai’i-Manoa

January 11, 2016

Harbor Acoustic Monitoring – Kilo Nalu Deployments – 2010, 2011

Boat, Diver Tracks Array, Rebreather Divers

August-Sept. 2011-Array Deployment

Underwater Pinger

Lubell (Underwater Speaker)

Deployment Location

PresenterPresentation NotesHydrophones were positioned on the seabed, separated by a 15m synchronisation cable, running perpendicular to one another. Other equipment used included an underwater source used to emit pings at timed intervals and a larger version which was tethered to the research vessel. The array was configured to record all 24 channels during the day and 3 channels during off-peak times for noise analysis.

Deployment- Acoustic Arrays

Aligning the arraysPlugging in the arrays

Preparation Arrays to seabed

PresenterPresentation NotesArrays were deployed and maintained by both observatory staff and a CIMES-employed post-doctoral researcher. Before each day’s activities, the array elements were checked to ensure they remained in the linear configuration.

Saturday, August 1st 2015 - 07:51 UTCUS Navy submarine successfully launches and recovers underwater drone

Scientific American, Feb. 2008

AUV - Military and Harbor Security Threat

REMUS-100 (Hydroid, Woods Hole, MA)

5 ¼ ft long, 7.5 in dia., 80 lbs5 knots maxBattery drivenDC brushless motorOpen, 3-blade propInternal navigation system

Cross Correlation (Two Phones)

• Cross-correlate two HLA phones (11m separation)

• Transform time-difference to look-angle

• Modem sounds follow GPS track• Track disappears between

modem sounds• Red line LOB computed from

Lat/Lon GPS coordinate

REMUS Modem

Small ship

GPS Track

REMUS passing

HLA

AUV- Acoustic Detection and Tracking

Directivity -REMUS-100 (Hydroid, Woods Hole, MA)

Small ship

GPS Track

REMUS Modem

Narrow Band Beam Forming ~(1065 Hz)

Cross Correlation

• Small boat• Single small outboard motor• Handheld GPS recorded location• GPS manually synchronized

against array clock– ~ 1 sec accuracy

Broadband noise source

Boat Localization• Current methodology:• Multiple pairs of sensors

– Hyperbola from each pair, look for intersection• Cannot deploy on mobile platform

Possible target location

Possible target location

• Can we get range & break left/right ambiguity using single pair?

• Multipath

Multipath – Star Wars: The Force Awakens

Multipath – Image Theory

receiver

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propeller

seabed

If we know depth of bottom reflection, we can predict correlation lag of each peak.

So, can we invert for the range/bearing?

bottom-surface image

Correlation lag times depend on:• bathymetry• target bearing• target range

PresenterPresentation NotesThis can also be analyzed using image theory.The source is reflected over the seabed, and again over the surface to obtain the bottom-surface image.Note that since the wave reflects off the surface, there is a change of sign.

Journal of Acoustical Society, 2013 and 2015

Ambient Noise–Kilo Nalu Observatory, Oahu HI

Gebbie, Siderius, Allen, Marine Science and Technology Journal, 2011Gebbie, Siderius, Allen, JASA-EL, 2012Gebbie, Siderius, McCargar, Allen, Pusey, JASA-EL, 2013Gebbie, Siderius, Allen, JASA, 2015Heei-Wai, Allen, Gebbie, Siderius, JASA (in submission)

Coconut Island - Shuttle Boat

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Recurrence Plot Dimension: 7, Delay: 56, Threshold: 0.04σ (fixed distance maximum norm, fixed RR)

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Recurrence Rate Detection

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1:30 0.009 Unclassified Acoustic Activity

5:45 0.0002 Pier to Lagoon

7:15 0.004 Lagoon to Lighthouse

9:10 0.0004 Lighthouse to Pier

11:15 0.004 Pier to Lighthouse

12:15 0.0004 Pier to Lighthouse (cont)

13:45 0.001 Lighthouse to Pier

15:20 0.009 Pier to Lagoon

17:30 0.02 Lagoon to Pier (Miss)

19:10 0.001 Pier to Lighthouse

20:00 0.0015 Lighthouse to Pier

23:00 0.0001 Pier to Record Site to Lighthouse25:10 0.0004 Lighthouse to Pier

26:45 0.0006 Pier to Lighthouse

27:30 0.003 Lighthouse to Pier

31:00 0.0001 Different Marine Vessel

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CFD Software –Adaptive Research, Inc.

Ice Acoustics - Research QuestionsAmbient Noise – Characterize Ice Cracking, Statistics, Directivity, Spectral Characteristics, Propagation, Temporal and Spatial Variability

Physical Mechanisms of Ice Cracking, Different from 1990s?

Acoustics Monitoring – Passive Acoustics

Can the sound of ice cracking be used tofacilitate target detection and tracking?

Can be used for environmental monitoring alone and conjunction with othermodalities?

Acoustics of Cracking Ice

X-Stream High-Speed 1000 – 30000fps

Optical, Acoustic and Mechanical- Salinity

Teager-Kaiser Energy OperatorThe instantaneous energy

Empirical Mode Decomposition

New Research Project (USDA, State of Hawaii) - Fall 2015, Jenkins (UH, CTAR)

Biosecurity: Acoustic Detection, Tracking and Mitigation of Invasive Species

Self-Avoidance, Detection, Tracking

Acoustics of Drones - Security, Navigation and Mitigation

Conclusions and Acknowledgements

Support: DHS CIMES, State of Hawaii, Hawaii Technology Development-ONR, NIH

Collaborators: Swinburne University, Portland State University, CTAR-UH

Students and Post-Docs: Tyler Heei-Wai, Rintaro Hayashi, Chris Layman, Grant Pusey, Melissa Yashinnski, Jonathan Chien, Brady Little, Bosco Huang

• Underwater Acoustics for Port and Harbor Security – Domestic and Foreign Harbors

• Physical Acoustics – Ice Fracture, Wakes, Bubbles,

• Engineering Acoustics – Drones, Invasive Species

Richard Manasseh1,2

Collaboration Topics with ARL -University of Hawaii

Image: Ocean Power Technologies Ltd.

1. Dept. of Mech. & Product Design Eng.2. Centre for Ocean Eng., Science & Tech.

PresenterPresentation NotesSave this template as a new PowerPoint Presentation, giving it the name you require OR copy these templates from Slide Master view into your existing presentation’s Slide Master optionsIf you go to >View > Slide Master you will see this template can be applied in Black, White or Grey background versions (which you will apply as you build or edit your presentation)Close Slide Master view. You can now construct your presentation.In the Slides area, select ‘New Slide’ to add a new slide. To apply a slide style to the new/highlighted slide - in the Slides area, select ‘Layout’ menu, select preferred slide style from the menu (eg. ‘Title and Content’) , select ‘Reset’.If you are updating an existing presentation, existing styles may not automatically update (hence using ‘reset’,) especially if the existing slide has not been produced with a template.Text from imposed text boxes may need to be cut & pasted into new auto-generated template text boxes etc.

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The title page ‘wave’ graphics can be increased in width, but not height.

Swinburne

Australian Research Council ranked 5/5 in Maritime Engineering

– top in Australia*

~$8M competitive grants over the last 5 years4 ARC Discovery projects3 ARC LIEF projectsCSIRO flagship project2 US Office of Naval Research projects1 ARENA project

Primary expertise: ocean wave physics

Industry projects: - Woodside Energy- Shell Corporation1* Since rankings began in 2012; received top rank again in 2015 1:

Centre for Ocean Engineering, Science and TechnologyCOEST

SwinburneFacilities for oceanography & acoustics

• 60 m wind-wave tank developed in partnership with University of Melbourne, generates cyclone-force winds, recently commissioned, with PIV

• Ice Wave Tank developed in partnership with University of Melbourne, (in progress)

• 10 m small-scale wave tank with random wave generator

• Wave probes

• Hydrophones

• Ultrasound transducers

• Micro-PIV

PresenterPresentation NotesAs waves grow under the influence of wind, they tend to break with the increasing steepness, and dissipate energy through various mechanisms. The appearance of 'white caps' is one of the indications of this dissipative process. It is generally believed that white capping is the dominant dissipative mechanism in a wave field at moderate and higher wind speeds - simply because other dissipative processes such as molecular viscosity and turbulence appear to be inadequate to remove the energy which is known to be imparted to the waves by the wind [Hasselmann (1974)]. This process of gravitational breaking is transient and initiated when wave becomes unstable. A number of attempts have been made to describe this highly nonlinear process of wave breaking - these include both experimental [Banner, Babanin and Young, (2000)] and theoretical studies [Banner and Young, (1994)]. Such studies generally consider it as an isolated phenomenon related to individual waves. In numerical modeling of waves, however, it must be formulated as a source term applicable to the wave spectrum. A number of approaches have been applied to model wave dissipation by breaking. Two of these approaches, the pressure pulse model [Hasselmann (1974)] and the quasi-saturated model [Phillips (1985), Donelan and Pierson (1987)] treat dissipation as a quasi-linear function of the wave spectrum, whereas the probability model [Longuet-Higgins (1969), Yuan et al. (1986)] considers it to be exponentially dependent on the wave spectrum.The pressure pulse or quasi-saturated models are deterministic. Observations of wave, however, indicate that white-capping is highly variable. There can be two waves, which for all practical purposes appear identical with same height, period and steepness. One will break and the other will not. Thus it may be appropriate to represent white-capping as a stochastic process where each wave is assigned a probability of white-capping, which proposed in probability model.The discussion above shows that whitecap dissipation is a process, which is poorly understood. No rigorous theory exists for either the onset of white-capping or the resulting energy loss, neither does an experimentally measured spectral dissipation function.

Swinburne

•Aim: automated detection of breakers and measurement of whitecap dissipation

• Co-ordinated video and underwater acoustic measurements at Lake George, NSW (Babanin, Young, Banner)

• Data re-analysed using pulsewise passive acoustic method

Wave breaking noise – due to bubble formation

Manasseh et al. 2006, J. Atmos. Ocean Tech. 23(4), 599–618.

Local wind-wave breaking

PresenterPresentation NotesAs waves grow under the influence of wind, they tend to break with the increasing steepness, and dissipate energy through various mechanisms. The appearance of 'white caps' is one of the indications of this dissipative process. It is generally believed that white capping is the dominant dissipative mechanism in a wave field at moderate and higher wind speeds - simply because other dissipative processes such as molecular viscosity and turbulence appear to be inadequate to remove the energy which is known to be imparted to the waves by the wind [Hasselmann (1974)]. This process of gravitational breaking is transient and initiated when wave becomes unstable. A number of attempts have been made to describe this highly nonlinear process of wave breaking - these include both experimental [Banner, Babanin and Young, (2000)] and theoretical studies [Banner and Young, (1994)]. Such studies generally consider it as an isolated phenomenon related to individual waves. In numerical modeling of waves, however, it must be formulated as a source term applicable to the wave spectrum. A number of approaches have been applied to model wave dissipation by breaking. Two of these approaches, the pressure pulse model [Hasselmann (1974)] and the quasi-saturated model [Phillips (1985), Donelan and Pierson (1987)] treat dissipation as a quasi-linear function of the wave spectrum, whereas the probability model [Longuet-Higgins (1969), Yuan et al. (1986)] considers it to be exponentially dependent on the wave spectrum.The pressure pulse or quasi-saturated models are deterministic. Observations of wave, however, indicate that white-capping is highly variable. There can be two waves, which for all practical purposes appear identical with same height, period and steepness. One will break and the other will not. Thus it may be appropriate to represent white-capping as a stochastic process where each wave is assigned a probability of white-capping, which proposed in probability model.The discussion above shows that whitecap dissipation is a process, which is poorly understood. No rigorous theory exists for either the onset of white-capping or the resulting energy loss, neither does an experimentally measured spectral dissipation function.

Swinburne

• Small-scale pilot experiments at Swinburne

• Experiments with a multiple devices and spacings at Australian Maritime College

• Co-ordinated modelling using semi-analytic approaches

Directional Wave Basin, AMC

Ocean Wave Power

Swinburne leads research funded by the Australian federal government (A$770K) in partnership with University of Tasmania and two leading wave-power companies

Develop fast, web-based software tool for policy-makers and investors to quickly assess the potential of arrays of wave-power machines

SwinburneOcean Wave Power

Partner projects

http://upload.wikimedia.org/0/07/Resonance.png

http://news.cnet.com/i/bto/20080527/biowave_home.jpg

Port Fairy demonstrator: successfully installed as planned, December 2015

Perth Wave Energy Array: successfully demonstration completed as planned over 2015

Carnegie Wave Energy Ltd

Biopower Systems

Future Research Directions – ARL

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Drones – Optical, Infrared, Hydrophones Ambient Noise – Diurnal Spectral Changes (real time)

Detection in Clutter – Multiscale Entropy

Ice Fracture and AcousticEmissions

Infrared Thermography

Underwater, Physical and Engineering AcousticsSlide Number 2August-Sept. 2011-Array DeploymentDeployment- Acoustic ArraysAUV - Military and Harbor Security ThreatSlide Number 6Cross Correlation (Two Phones)AUV- Acoustic Detection and Tracking Slide Number 9Boat LocalizationMultipath – Star Wars: The Force Awakens Multipath – Image TheorySlide Number 13Slide Number 14Ambient Noise–Kilo Nalu Observatory, Oahu HISlide Number 16Coconut Island - Shuttle BoatPath Repetition and RecurrenceRecurrence Rate DetectionSlide Number 20Ice Acoustics - Research QuestionsAcoustics of Cracking IceSlide Number 23Teager-Kaiser Energy OperatorEmpirical Mode DecompositionSlide Number 26Biosecurity: Acoustic Detection, Tracking and Mitigation of Invasive Species Slide Number 28Conclusions and AcknowledgementsSlide Number 30Slide Number 31Slide Number 32Slide Number 33Slide Number 34Slide Number 35Future Research Directions – ARL