SCAMPI : Sub-seafloor Characterization by Acoustic Measurements & Parameter Inversion :
SCAMPI is a patented system for the sub-seabed investigation. It aims to identify and characterise the sediment layers over a thickness of 5 to 10 meters below seabed. Major physical parameters – compressional seismic velocity and grain size – are, then, quantified without carrying out mechanical sampling.
The SCAMPI technology is based on the propagation of acoustic waves between a source and a multichannel receiver, towed behind the vessel. The processing deals with both water and sediment multipath and allows the binning of information at each common midpoint between source and receiver, similarly to the seismic reflection technique.This new technique can be assimilated to “shallow digital acoustic marine, multi coverage, ultra high resolution”
Signal processing :
The proprietary processing computes the various travel paths between source and hydrophone – direct, reflected on sea surface, reflected on sea bottom and sub-seabed interfaces – and gathers information for each common-midpoint. As the system moves forward, and thanks to the logging of shot and hydrophones GPS position, a binning phase allows the processing to stack information at each commonmidpoint. Hence the same layer interface is sampled several times with different grazing angles.This multi coverage signal processing authorizes the characterisation of each layer with essential parameters (compressional and shear velocity, density, attenuation) and the ultra high resolution of interface position.
System Advantages :
- Computation of velocity vertical profile, for each identified layer, at each shot
- Identification of low-velocity layer intrabedded within high-velocity layers
- Survey speed allowing a fast coverage of the studied area
- Risk-free survey, for the spread, as no equipment is dragged on the sea bottom
- No limitation in deep waters
- Investigation and characterisation of the full range of marine sediment