Field and Laboratory Equipment |
Field Equipment
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RV Pelican: This research vessel is frequently used by the Pelican lab to conduct acoustic surveys as well as coring operations. The RV Pelican has been used throughout the Chesapeake Bay, along the Eastern Shore, and in the nearshore of the Outer Banks. |
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BASIR: The Bar And Swash Imaging Radar (BASIR), developed in collaboration with Imaging Science Research and supported by the Army Research Office, uses a 9.4 GHz radar to measure the location of breaking waves from a mobile platform positioned on the beach. BASIR is being used to study the spatial and morphologic changes within the nearshore. By mounting the radar on a mobile platform, we can quickly respond to storm events over large spatial regions giving BASIR an advantage over traditional tower mounted video or radar imaging systems. |
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Trimble RTK DGPS: This highly accurate, mobile global positioning system allows horizontal and vertical accuracy up to 2 cm. The system is used to provide vertical control for both ship mounted seismic surveys as well as ATV mounted beach profiling. Repeated surveys using the RTK provide insight into long-term beach and nearshore erosion and accretion patterns. |
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Edgetech Chirp Sub-bottom Profilers: These systems are used to image the stratigraphy of the seafloor. These frequencies can penetrate up to 50m.
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Sparker: The sparker is a relatively higher powered sound source, dependant on an electrical arc which momentarily vaporizes water between positive and negative electrodes (Trabant 1984). The collapsing bubbles produce a broad band (50 Hz - 4 kHz) omni-directional acoustic pulse. Sparkers typically yield better penetration, but poorer resolution than boomer systems, with depth of penetration up to 500 metres (Stoker et al., 1997), and vertical resolution usually greater than 2 metres (depending on energy settings). Sparker sources are commonly used in regions where compacted sands and other coarse semiconsolidated sediments are found. Some sparker seismic systems have been developed in which the electrical discharges take place at the focus of a paraboloidal reflecting surface, in order to obtain a downward-oriented, approximately plane acoustic wavefront. This system enables a greater substrate penetration (Gasperini et al., 1993). |
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Huntec Boomer: Boomer sub-bottom profilers comprise an insulated metal plate adjacent to an electrical coil, typically mounted on a towed catamaran. This electro-mechanical transducer is known as a ‘boomer plate’. A powerful electrical pulse, generated by a shipboard power supply and capacitor banks discharges to the electrical coil, causing a magnetic field to explosively repel the metal plate. This energetic motion generates a broad band, high amplitude impulsive acoustic signal in the water column (Trabant 1984, McGee 1995). The frequency of the acoustic pulse is in the range 300 Hz to 3 kHz (or more) with the majority of the energy being directed vertically downward (Verbeek and McGee, 1995). Most boomer systems rely on a (potentially dangerous) high voltage power supply and capacitor banks for the generation of the high voltage electrical pulses required. More recent developments in efficient, low voltage boomer systems have circumvented some of the problems inherent with the high voltage systems (Davis et al., 2002). Resolution of boomer systems ranges from 0.5 to 2 m, and penetration typically ranges from 50 to 200 metres, depending on sediment type. A limitation of these systems is that the transmitted acoustic pulses do not have the repeatability necessary to provide high accuracy measurements of seafloor properties.
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Interferometric: The high frequency ( kHz) interferometric system is used to generate bathymetric maps of the seafloor. The backscatter is analagous to a relatively low frequency side-scan system. Similar to a multibeam bathymetric system, the multiple recievers in the interferometric system measure the phase change of the returning signal, allowing data to be collected in very shallow waters(< 5 meters). |
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Ocean Systems Sidescan Systems (900 and 1200 kHz): The high frequency sidescan sonar systems can map seafloor structures on various spatial scales ranging from small ripples to submarine canyons. When ground-truthed sidescan sonar data can be used to map variations in grain-size of surficial sediment. Recently this system was used to map Queen Anne's Revenge off of the Outer Banks, NC. |
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Vibracore: The vibracore is an effective tool for coring in coarse grained or highly compacted sediments. Simple gravity cores such as the box and kasten core are unable to penetrate this coarse sediment and collect shorter cores compared to the vibracore. The longer cores collected with the vibracore allow for ground truthing of the stratigraphic record as imaged by the various low frequency seismic systems. |
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Lab Equipment & Software |
IVS 3D Fledermaus Pro: This professional suite of programs allows for detailed editing of bathymetric data in 3D. In addition it is a powerful data visualization software package which can combine bathymetry with georeferenced sub-bottom profiles, shorelines, topographic and bathymetric charts, aerial photographs, lidar data, etc. |
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Chesapeake Technologies Inc. Sonarweb Pro: This software program is used to process sub-bottom data including digitizing key reflectors, calculating thicknesses of lithologic units, and exporting the data. |
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Chesapeake Technologies Inc. SonarWiz.MAP This software program is used to process sidescan data. |
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Hypack: Survey mapping software. |
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Additional Processing Software: 1) Surfer: This data mapping software is used primarily for constructing isopach maps. 2) Strater: This software is used primarily for generating fence diagrams. |
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| Rapid Sediment Analyzer: currently under construction. Here is a sketch of the settling tube design. The RSA will be used to separate coarse-grained material into different size-classes. |
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