Overview & Scope As well at sea as in waterways, G-tec implements different techniques to provide an appropriate and customized solution in hydrography and in land waterways for underwater works, such as bathymetric survey, imaging, real-time 3D visualization, ROV inspection, seismic refraction, underwater cartography, G-tec provides data acquisition, processing and interpretation for : 
Skills and Capabilities |
Single- and Multibeam sonar - Bathymetry
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| These techniques provide accurate bathymetric data, essential in operations such as:- Underwater cartography
- Port/Lake/Waterways development
- Dredging works
- Volume calculation
- Silting up/erosion assessment
- Pipeline inspection
- Bank surveying
- GIS and mapping
Bathymetrical survey are realized with : - Singlebeam echosounder
- Multibeam echosounder
- GPS RTK positionning system
- Heading sensor
- Motion sensor
- Sound velocity probe
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Imaging sonar
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| Imaging sonar is high frequency imaging solution, providing clear and detailed real-time underwater images. Imaging sonar is recommended for activities such as :- Inspection of hydraulic works (dams, locks)
- Seabed mapping (outcrops, mud, pebbles)
- Detection of irregularities in concrete (quay wall, slab)
- Targets location (wrecks, various objects, scouring...)
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Refraction Seismics (UTSR)
|  | L ightweight, efficient, cost effective system, G-tec’s UTSR is ideally suited for bedrock characterization in various conditions.
- Easily adaptable system according to site conditions
- Differentiation between sediments and bedrock
- Assessment of the compactness of the bedrock
- Determine weathering or fracturation of a rock mass
- Real-time data processing
- In water depths ranging from 1 to 100 meters
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Underwater real-time 3D visualization (EchoscopeTM)
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| The Echoscope is a new high resolution sonar device producing instantaneous 3D acoustic images of both moving and stationary underwater objects.
Inspection & work progress monitoring : - Vertical structures (e.g. quay walls, spuds, etc.)
- Rock structures (e.g. breakwaters, etc.)
- Erosion protection
- Detection and characterisation of obstructions (e.g. objects, wrecks, anchors, pipelines, etc.)
Online monitoring in dredging & submarine works: - Dredging (TSHD / CSD / BHD)
- Environmental monitoring (e.g. turbidity)
- Placement of spuds in sensitive area (e.g. jack-up platform)
- Replacing or assisting in diving operations
- Cable installation
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| Gradiometer magnetometry - UXO detection |  | A large number UXO detection surveys have been carried out using gradient magnetometry, resulting in the detection of unexploded Naval Mines, bombs and grenades. |
| Side Scan Sonar |  | A side scan sonar is an instrument that uses ultrasonic fan-shaped pulses to produce high resolution images of the seafloor. Contrary to other methods, like seismic reflection, side scan sonar is entirely dedicated to bottom imaging. It is usually towed behind a boat and can fully cover large areas in a short time. It can be used to detect objects on, or characterize the nature of the bottom. The former can be done by examining and measuring the targets spotted on the data, and particularly the shadows they cast, the second by comparing areas with different intensity of reflection: the lesser the intensity, the softer the material on the bottom. - Detection and characterization of obstructions (e.g. objects, boat or car wrecks, anchors, pipelines, etc.)
- Pipe or cable surveys.
- Wreck and UXO Detection.
- Control and monitoring of rock dumping
- Seabed classification
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