Hydrographic & Geophysical Surveys
Artist's rendition of typical swath bathymetry coverage of the seafloor. Courtesy of Reson, Inc.
Substructure conducts hydrographic and geophysical surveys to support a variety of activities: port and harbor maintenance (dredging), pipeline and cable crossing surveys, dam face inspections, archaeological recovery, and coastal engineering (beach erosion and replenishment studies).
Data types of interest include depth of seawater, the nature of seafloor material, magnetic anomalies, and the composition of sub-bottom strata.
Substructure utilizes, among other tools, both multi-frequency single beam and multibeam echo sounders, side-scan sonar, magnetometers and sub-bottom profilers to generate the data required by our clients’ diverse needs.
Worldwide Hydrographic Surveys
Substructure has performed hydrographic surveys throughout the world. We have surveyed locations along the eastern seaboard of the United States from Maine to Florida, as well as international sites from Ireland to Peru.
Advanced Survey Vessels
Substructure has completed its latest and most advanced survey vessel, Orion. This vessel has an overall length of 31’6” and is equipped with a medium speed tractor jet drive system from North American Marine Jet. This medium speed jet has very little impeller cavitation at low speed and the jet drive shaft rides on bearings both fore and aft of the impeller, thus reducing any end-play and associated vibration.
Reson SeaBat 8125 Multibeam Echosounder
Orion is built to utilize the Reson SeaBat 8125 Multibeam Echosounder. This system is a 455 kHz sonar unit that is hull-mounted, although the array can be angled for surveys of dam faces or other vertically-oriented surfaces. The modular through-the-hull mounting system is capable of accommodating a variety of sensors through the addition of a mounting bracket fitted for the sensor of choice.
The system transmits 240 dynamically focused beams measuring depths across a 120 degree swath of the seafloor generating soundings at up to 40Hz. With a depth resolution of 6 mm, an across-track beam width of 0.5 degrees, and an along-track beam width of 1 degree, the Reson SeaBat 8125, as implemented on Orion, is capable of consistently providing IHO Special Order accuracy and USACE Special Order accuracy.
The Latest In Subsurface Data Acquisition
The Reson 8125, combined with an advanced navigation system, position and orientation and heave sensors, a sound speed profiler, and several additional ancillary components, makes up the backbone of the survey system on board Substructure’s latest vessel. Coupling these with advanced magnetometer and sub-bottom profiler capabilities rounds out the technical package and provides for the latest in subsurface data acquisition.