Diver Visibility and Environmental Optics Sensor for AUVs: SAM

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Diver Visibility and Environmental Optics Sensor
for AUVs SAM

• Michael Twardowski
• WET Labs, Inc., Narragansett, RI
• mtwardo_at_wetlabs2.com
• Ron Zaneveld and Casey Moore, WET Labs, Inc.
• Oscar Schofield, Rutgers University
• Tyler Helble, SPAWAR

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Diver visibility and attenuation
Backscattering is NOT a good proxy for visibility
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COTS beam attenuation meter
WET Labs c-star
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Visibility and Attenuation Sensor installed on a
glider AUV
Webb Slocum glider
Rutgers glider team
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SAM Visibility and Attenuation Sensor
PROBLEM To measure attenuation accurately in the
ocean, you need to measure it over long
pathlengths. How do you do that with a compact
sensor?

• SAM Scattering and Attenuation Meter
• Principle 2 measurements of scattering are made
  at the same angle, but over different pathlengths

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Comparison with conventional attenuation
measurements
Long Island Sound 2004
59,290 data points, no binning
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SAM Applications
-Visibility (and vulnerability) -Environmental
optical data
Divers Active EOID Passive EOID

• Mine counter measure operations
• Harbor security operations
• Debris field mapping
• Environmental monitoring
• Scientific sampling and research

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Visibility and Attenuation in San Diego Harbor
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REMUS Bottom Imaging in San Diego Harbor
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New York Ship Channel
Over XXXX h of SAM data logged on the RU Slocum
glider AUVs through XXXX km of coastal waters
After over 1000 h of use, no detectable change in
calibration parameters
Rutgers glider team
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Visibility Observations

• Visibility and attenuation change rapidly over
  small spatial scales (m) in coastal waters,
  ports, and harbors
• Turbid bottom nepheloid layers are ubiquitous in
  coastal waters, ports, and harbors
• Visibility and attenuation levels in coastal
  regions typically fall in ranges that strongly
  affect the efficiency and success of defense and
  security operations
• Attenuation is a more accurate proxy for diver
  visibility than backscattering

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MCM EOID performance prediction
EODES-3 Tactical Decision Aid

• Model optimized for AN/AQS-24 laser line scan
  systems
• Model input is SAM attenuation data

METRON, Inc. www.metsci.com
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SAM visibility diver package

• Training

• Visibility (and vulnerability) when obvious
  targets and distance metrics are not available

Wireless dive watch displaying visibility
Battery and on-off switch
Diver SAM with wireless data comms
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RD Offspring of SAM
Thank you

• Lower power consumption
• Full on-board processing
• Easier to manufacture
• Enables further sensor miniaturization
• Can accommodate further enhancements

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Can Backscattering be Used for Visibility
Measurements?
NO
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