Geophysical
Surveys
SEI’s hydrographic and geophysical survey capabilities were developed to complement our ocean and coastal engineering capabilities. Our range of services includes planning, positioning, surveying, data interpretation and map production. Hydrographic, side scan, sub-bottom and magnetometer surveys have been completed for pre- and post-dredging comparisons, ocean outfall route selection, fiber optic cable landings, aircraft recovery, unexploded ordnance mapping and for general planning studies.
Available equipment includes:
Positioning
Trimble 4000 RS/Ds differential GPS with real time sub-meter accuracy
Multibaud UHF telemetry system with a range of 20 miles
Trimble AgGPS 132 Differential GPS
C-NAV GPS 2000
Side Scan Sonar
C-Max CM2 102/325 kHz side scan sonar
Bathymetry
Odom Hydrotrac Precision Survey Fathometer
Odom Echotrac Model 3100 Survey Fathometer
Odom Echoscan Multibeam Survey System
Sub-bottom
EdgeTech X-Star 216 sub-bottom profiler
Edgetech X-Star 408 sub-bottom profiler
Survey Integration
Hypack survey software capability includes survey design, vessel navigation and positioning, on-board data integration, data review and processing, plotting and dredge volume computations. Post processing software allows data sorting, contour, plan and cross section plots, dredge templates and volume calculations. Data can be presented in ASCII, CAD and DXF formats.
Representative Projects
Pearl Harbor, Oahu (2006-2007)
Sea Engineering, Inc. performed a multi beam survey of all of West Loch channel in Pearl Harbor.
Client: U.S. Army Corp of Engineers
Costa Rica, Mexico, California, Madagascar, Papua New Guinea (2006-2007)
Sea Engineering, Inc.
has conducted several fiber optic cable landing surveys in various locations. Surveys include sub bottom profiling, side scan sonar, single beam echosounder, towed video, diver swims, and land surveying.
Client:
Various
Pago Pago Harbor Hydrographic Survey, American Samoa (2001)
Sea Engineering, Inc. conducted an automated hydrographic survey of Pago Pago Harbor. The work area extended from the inner harbor to the 300-foot water depth beyond the harbor entrance, a distance of approximately six miles. Particular care was taken to include the edge of the fringing reef that rings the harbor, and also any channels or significant irregularities in the reef. The survey information was used to support numerical modeling of proposed harbor improvements by the Corps of Engineers. Click here to see a representation of our data collection.
Client: U.S. Army Corp of Engineers
Ehime Maru Recovery Site Surveys (2001)
Sea Engineering conducted detailed bathymetry, side-scan and sub-bottom surveys of possible staging sites for the recovery of the Japanese fisheries training vessel, Ehime Maru. Bottom morphologies were mapped, and the data were presented in 3-D perspective plots, plan view contour plots, and isopach plots of sediment thickness. Sea Engineering recently received the "2001 CNO Environmental Planning Team Award" from CINCPACFLT as a member of the team responsible for the environmental planning in support of recovery efforts for the M/V Ehime Maru.
Client: U.S. Navy, Pearl Harbor, Hawaii
Pipeline Positioning for Construction of an Offshore Oil Delivery Pipeline, Acajutla, El Salvador (1995)
During construction of an offshore oil delivery system in Acajutla, El Salvador, Sea Engineering was responsible for a site hydrographic survey; geodetic engineering; positioning for five offshore mooring emplacements; barge positioning for pulling two kilometer long twin offshore oil delivery pipes; and underwater positioning of the pipeline end manifold. SEI used a Trimble 4000 RS/DS differential GPS system for submeter surface positioning, and integrated DGPS with a Trackpoint II acoustic tracking system for the underwater positioning. SEI was also responsible for post construction underwater mapping and as-built drawings of the pipeline route and pipeline end manifold.
Client: Weeks Marine, Inc.
Investigation of Shelf Sand Resources in Hawai`i (1996)
As part of a U.S. Geological Survey multiyear project to study shelf sand resources in Hawai`i, Sea Engineering conducted high resolution sub-bottom surveys and remote sediment classification is selected areas in Hawai`i. Our responsibilities included survey logistics, positioning, sub-bottom profiler operation, and data processing.
Client: U.S. Geological Survey, Menlo Park, CA
Barbers Point Harbor Prototype Ship Motion Study (1999)
SEI conducted investigations of wind, waves and currents and the motion of large deep- draft vessels entering and exiting Barbers Point Harbor on Oahu. This work assisted the U.S. Army Corps of Engineers, Waterways Experiment Station, with their ongoing investigation of large vessel navigation design parameters. A wave gage, current meter, tide gage and anemometer were installed in the harbor entrance channel to record environmental data during the 30 day study period. A shore based Kinematic GPS base station was installed to provide an accurate horizontal and vertical reference station. SEI personnel then boarded vessels at-sea before they entered the entrance channel or in the harbor before departing, installed KGPS receivers on the port and starboard wings and the bow, and recorded vessel movement as it traversed the channel. Required accuracy was 1-5 cm both horizontally and vertically. The environmental and ship motion data was then provided to WES for their analysis.
Client: U.S. Army Corps of Engineers, Waterways Experiment Station, Vichsburg, Mississippi
Unexploded Ordnance Survey for Extension of the Sewer Outfall at Fort Kamehameha, Pearl Harbor Naval Station (1999)
SEI conducted a survey for unexploded ordnance along 3,000 meters of a proposed new outfall route off the entrance to Pearl Harbor. The route was surveyed for buried ordnance using a Geometrics Cesium Vapor Magnetometer. Differential GPS was used for survey navigation and positioning, with magnetometer survey lines run along the route at two meter spacing. Magnetic anomaly data were processed using Geosoft’s OASIS Montaj data processing software to locate and characterize potential UXO targets.
Client: Pacific Division, Naval Facilities Engineering Command
Bathymetric Surveying
Numerous harbor condition surveys and pre and post dredging surveys have been completed including
Sub-Base Berthing Pier (Pearl Harbor, 1999), Piers 15-20, Honolulu Harbor (1996), Hawaii Kai Marina (1996), Barbers Point Harbor expansion (1999) and WharvesY-2 and K-1 (Pearl Harbor, 1996).
FIBER OPTIC CABLE ROUTE SURVEYS
SEI has completed nearshore route surveys around the world for fiber optic cable systems. The surveys typically include bathymetry, side scan sonar imaging, sub-bottom profiling, geologic interpretation, diver route reconnaissance, location and tracking of existing cables, video surveys and chart production.
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Equipment EdgeTech X-Star 216 sub- C-Max CM800 102/325 kHz side scan sonar Odom Hydrotrac single beam echosounder Trimble 4000 differential GPS JW Fisher Pulse 8X diver metal detector Geometrics 880 magnetometer |
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Completed near-shore fiber optic cable route surveys: Southern Cross Cable Fiji Kahe, O`ahu North Kahe, O`ahu Spencer, Hawai`i Monterey, California Morro Bay, California |
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Japan – U.S. Cable Makaha, O`ahu Morro Bay, California Point Arena, California
Americas-II Cable Hollywood, FL San Juan, Puerto Rico Martinique - Fort-de France, Martinique
Atlantic Crossing I Cable Shirley, Long Island, NY |
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GST/Pacific Telecom Cable Sandy Beach, O`ahu Makaha, O`ahu Manele, Lana`i Kaunakakai, Moloka`i Mokapu, Maui Spencer Beach Park, Hawai`i
GTE Hawaiian Tel Cable Kahe, O`ahu Sandy Beach, O`ahu Mokapu, Maui Spencer Beach Park, Hawai`i Wailua, Kaua`i |
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TGN Pacific Cable Lualualei, O`ahu Mākaha, O`ahu Kahe, O`ahu Poka`I Bay, O`ahu Agat, Guam Piti, Guam |
360networks Pacific Mākaha, O`ahu Lahilahi, O`ahu Ko`Olina, O`ahu |
Please contact Sea Engineering, Inc. for any additional information.