Torstein Olsmo Sæbø

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The success of synthetic aperture sonar (SAS) is critically dependent on overcoming several challenges. The sonar has to be positioned with accuracy better than a fraction of a wavelength along the synthetic aperture. The ocean environment, and particularly the sound velocity, has to be accurately estimated for successful focusing of SAS images. For(More)
interferometry (based on the interferogram) is tested on the full swath and objects. Coarse bathymetry is more reliable than the interferogram technique. Phase wraparounds are avoided by estimating the coarse bathymetry first, then using the full resolution phase estimates as correction. Although much work remains, this technique does show a clear potential(More)
Synthetic aperture sonar (SAS) interferometry can provide bathymetric maps of the seafloor with high resolution over large swaths. Traditional narrowband interferometry relies on advanced phase unwrapping techniques to resolve phase ambiguities. For wideband systems there are alternative techniques to estimate the absolute (or ambiguity-free) phase(More)
Successful synthetic aperture sonar (SAS) imaging is dependent of several challenges to be overcome. The sonar has to be positioned with accuracy better than a fraction of a wavelength along the entire synthetic aperture. At 100 kHz this equals an accuracy requirement around 1 millimetre along tens of metres of travelled distance. The ocean environment, and(More)
Collection of synthetic aperture sonar (SAS) data along a circular track and forming a circular SAS (CSAS) image has several benefits over traditional stripmap SAS: the area of interest is observed from all aspect angles giving a better perception; the resolution in the image increases and shadow zones are avoided. Navigation requirements however, become(More)
Measurements of acoustic backscattering from glacially eroded rock outcrops were made off the coast of Sandefjord, Norway using a high-frequency synthetic aperture sonar (SAS) system. A method by which scattering strength can be estimated from data collected by a SAS system is detailed, as well as a method to estimate an effective calibration parameter for(More)
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