Use of towed deepwater video systems at CSIRO Marine Research

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Use of towed deepwater video systems at CSIRO
Marine Research

• Direct sensing of the size and abundance of
  target and non-target fauna in Australian
  fisheries A National Workshop FRDC 2000/187

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Use of towed video

• Understand nature and extent of seafloor types
  and their relationship to inhabitants
• complement other sampling tools, on distribution
  of fauna
• verify seafloor types as observed using hydro
  acoustic techniques
• use in conjunction with acoustic techniques to
  map habitats

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Overview of presentation

• recent developments of towed underwater video
  systems at CSIRO Marine Research
• issues relating to the use of video in open ocean
  environments
• image scaling techniques adopted
• future needs for video to survey the seafloor

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Players - CSIRO Marine Research

• Marine Technology Information (MTI) - Ocean
  Engineering
• MTI - Electronics
• MTI - Engineering Technical Services
• Multiple Use and Management EEZ (MUMEEZ)
  Researchers
• MUMEEZ Research Support

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Kursk- Berents Sea
Rescue efforts 102 metres water Exposed open
ocean Poor visibility 118 lives
THIS IS A DIFFICULT ENVIRONMENT TO WORK IN! or
Dont consider using submersibles!
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Needs

• quality video of seafloor from a stable platform
• shelf to mid-slope depths (20-1500m)
• exposed open-ocean conditions
• areas with high current and turbidity
• low light
• over various bottom types including high-relief
  outcrops
• transect sampling

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Tow configuration of platform
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Proven ability

• stable platform
• constant height above bottom
• ability to operate in open-ocean conditions
• transit the seafloor over a variety of bottom
  types including high-relief outcrops and boulder
  fields
• operates in current-swept environments
• cloned and successfully operated around Aleutian
  Isands fishery, Alaska

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Features

• 80 minutes in-situ recording
• Optional stereo capability (two cameras)
• Laser Measure four-laser configuration for image
  scaling
• Tracking system (Sonardyne)
• System performance feedback

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System

• Sony DSR PD100 digital video cameras
• 2 x 250 Watts lights (DeepSea Multi-Sealite)
• 6 x 10mW 635 nm laser array
• Altimeter (Datasonics)
• Transponder for tracking (Sonardyne 7970)
• Electronics unit with pitch, roll, pressure and
  temperature sensors and data communications

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Real-time feedback display
Custom Labview feedback display
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Wire and winch

• Double armoured wire cable
• 4 twisted pairs and 5 single conductors
• electric hydraulic winch with level-wind
• adjustable brake

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Data logging
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Lacepede Shelf - 80 metres
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South Eastern Fishery - 120 metres
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Macquarie Island - 850 metres
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St Helens Hill - 800 metres
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Muirfield Seamount - 550 metres
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The Horseshoe canyon - 1500 metres
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Limitations

• Expensive
• Lack of control - difficult to examine features
  in detail
• Moderate level of support required for operation
• No real-time video on vessel
• Element of risk operating in areas with
  high-relief outcrops/overhangs
• Lengthy deployment and retrieval time with
  two-body configuration

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Analysis

• One record per second to score small
  spatial-scale variability
• Database links each record to gear position or at
  least vessel position
• Descriptors for scoring substratum,
  geomorphology, fauna, fauna abundance
• Frame grabs of specific areas of interest or
  fauna
• Use of Laser-Measure for size and abundance
  measurements

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Image scaling and size measurements

• Laser Measure (ex MBARI)
• Four laser array
• Image analysis using Optimas with macros to
  create transform grid based on relative position
  of laser dots in image

• Stereo video
• Under development
• Application for X,Y Z measurements
• Possible collaboration with Tas Uni
  photogrammetrist on measurement of krill

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Future Developments

• Fibre-optic cable for real time video on board
• Another 3000 metre rated version
• Thrusters for height-above-bottom control
• Digital stills camera (4 megapixel) for
  high-resolution images of seafloor
• Enhanced ability to make accurate measurements
  from images

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Acknowledgments

• CMR Marine Technology Information program - Ian
  Helmond, Matt Sherlock, Jeff Cordell, Lindsay
  MacDonald, Dave Kube, Bob Driscoll, Terry Byrne
• CMR Researchers and research support - Nic Bax,
  Alan Williams, Alan Butler, Tony Koslow, Rudy
  Kloser, Mark Lewis
• Dr Daniel Davis of Monterey Bay Marine Research
  Institute for Laser Measure
• Special thanks to those in MTI who worked to
  extremely tight deadlines yet still made
  everything work marvellously
• Conveners and organizers of this workshop
• FRDC

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Some other issues

• Long term data storage
• Accessibility of video data

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Very relieved bunch to see it back on deck