Seafloor Mapping Technologies
Maritime Alliance Symposium
San Diego, August 2011
By: Michael Broadbent
Fugro Pelagos Inc.
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Fugro Overview
• Fugro is an international surveying,
geosciences, and geotechnical services
company that collects and interprets data about
the earth’s land masses and oceans.
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Large company with true global reach
Extensive and innovate capabilities
Unique world wide operational experience
Sole focus on mapping our planet
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Vessel Based Multibeam Surveys
Multibeam bathymetry creates swathes of survey data
that map underwater surfaces and features
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Uses sound (sonar) pulses to map the seafloor
Improvement on single beam (profiling) sonar
Methods and sensors able to map the deepest parts of the seafloor
Variable swath width (width vs. detail)
Some sensors capture backscatter intensity (snippets) allowing
imaging of the seafloor
SB
MB
WA
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Underwater Infrastructure
INTACT PIPELINE
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Bathymetric Port/Harbor/Coastal Chart
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Sonar Backscatter (Side-Scan or Snippets)
Side-scan sonar (or snippets) can be
utilized for creating an image of the floor
of the water body/water course.
Ship Wreck
Data collected can help identify the
composition and texture of the
seabed/lakebed/riverbed.
Ship Wreck
Rock Piles
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Marine Geophysics – Seismic Reflection
Variety of different seismic systems for shallow and deep
water investigations.
Provide valuable information regarding the sub-bottom
geology for dredging or construction applications as well as
evaluating sediment transport issues.
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Marine Geophysics
• Different seismic sources: chirp, boomer or spark
• Different receivers: single/multi-channel
• Data interpreted with core samples to produce geological maps
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Autonomous Underwater Vehicles
• Often designed for surveys down to
10,000’ below sea level
• Offer the most detailed surveys of deep
seafloor
• Vessel deployed or land deployed
• Variable sensor packages including:
• Bathymetric survey
• Sidescan Sonar
• Geophysical Profiling
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AUV Deep Water Advantages: Bathymetric Survey
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Better Bathymetry Data in Deepwater
Hull-mounted vs. AUV Multibeam data
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Breakwater Survey: San Pedro, California
Angel’s Gate
Lighthouse
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Port Infrastructure
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Offshore Platforms & Terminals
• Annual Inspection
• Hurricane Damage
• Pre/Post Retrofit
• Clash Detection
• Decommissioning
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Airborne LiDAR Bathymetry
Airborne Bathymetric LiDAR
– Uses green and NIR laser
– Green laser penetrates the water
column to 2 x Secchi depth
– Measures timing and intensity of
returned laser pulse
– Simultaneous digital imagery
– Reduced risk, time, and cost
compared to vessel based hydro
surveying
– Requires clear water to operate
– Scans at 1 KHZ side to side to
produce swath coverage
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Airborne LIDAR Bathymetry Operational Concept
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CMP USACE NCMP
West Coast LiDAR Mapping
(1,000 m)…………..Hydro & Topo………(500 m)
•Hydro – waterline to 1,000 m
•Topo – waterline to 500 m
•Imagery @ 20 cm resolution
•Hyperspectral
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Lidar Bathymetry Reflectance
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Jizan, Kingdom of Saudi Arabia
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Conclusion
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Right Tool for the Right Job:
– Each project will have demands appropriate for a different survey
technology
Integrated Interpretation Strategy:
– Many features can only be properly characterised by the use of multiple
data types
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Thank You!
Contact info:
Michael Broadbent
mbroadbent@fugro.com
•www.fugro.com