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Seafloor Mapping Technologies. Maritime Alliance Symposium. San Diego, August 2011 By: Michael Broadbent Fugro Pelagos Inc. Fugro Overview.
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Seafloor Mapping Technologies Maritime Alliance Symposium San Diego, August 2011 By: Michael Broadbent Fugro Pelagos Inc.
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. Large company with true global reach Extensive and innovate capabilities Unique world wide operational experience Sole focus on mapping our planet
Vessel Based Multibeam Surveys Multibeam bathymetry creates swathes of survey data that map underwater surfaces and features • 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
Underwater Infrastructure INTACT PIPELINE
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. Data collected can help identify the composition and texture of the seabed/lakebed/riverbed. Ship Wreck Ship Wreck Rock Piles
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.
Marine Geophysics • Different seismic sources: chirp, boomer or spark • Different receivers: single/multi-channel • Data interpreted with core samples to produce geological maps
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
Better Bathymetry Data in Deepwater Hull-mounted vs. AUV Multibeam data AUV Deep Water Advantages: Bathymetric Survey
Breakwater Survey: San Pedro, California Angel’s Gate Lighthouse
Offshore Platforms & Terminals • Annual Inspection • Hurricane Damage • Pre/Post Retrofit • Clash Detection • Decommissioning
AirborneLiDAR 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
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
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 Conclusion
Thank You!Contact info:Michael Broadbentmbroadbent@fugro.com