Browsing by Author "Sæbø, Torstein Olsmo"

3D Rendering of Shipwrecks from Synthetic Aperture Sonar

Lorentzen, Ole Jacob; Hansen, Roy Edgar; Sæbø, Torstein Olsmo; Synnes, Stig Asle Vaksvik; Geilhufe, Marc (2021-10-25)

Synthetic aperture sonar (SAS) bathymetric mapping provides centimeter-scale horizontal resolution of the seafloor. Typically, SAS data has been visualized as 2D images or gridded 2.5D surfaces, but it can also be plotted ...

Adaptive phase estimation filter in long range synthetic aperture sonar interferometry

Sæbø, Torstein Olsmo; Hansen, Roy Edgar (2023-05-15)

Synthetic aperture sonar (SAS) interferometry is a technique for very high resolution imaging and mapping of the seabed. In SAS interferometry, the seabed depth estimation performance is a function of the system, the ...

Automatic detection of marine gas seeps using an interferometric sidescan sonar

Blomberg, Ann Elisabeth Albright; Sæbø, Torstein Olsmo; Hansen, Roy Edgar; Pedersen, Rolf B.; Austeng, Andreas (2016)

There is a significant need for reliable, cost-effective, and preferably automatic methods for detecting and monitoring marine gas seeps. Seeps at the seafloor may originate from natural sources including sediments releasing ...

Challenges in Seafloor Imaging and Mapping With Synthetic Aperture Sonar

Hansen, Roy Edgar; Callow, Hayden John; Sæbø, Torstein Olsmo; Synnes, Stig Asle Vaksvik (2011)

Synthetic aperture sonar (SAS) is emerging as an imaging technology that can provide centimeter resolution over hundreds-of-meter range on the seafloor. Although the principle of SAS has been known for more than 30 years, ...

Challenges of Automated Change Detection in Repeat-pass Synthetic Aperture Sonar Imagery

Midtgaard, Øivind; Sæbø, Torstein Olsmo; Warakagoda, Narada Dilp (2023)

Change detection extracts regions of interest as temporal differences by imaging a scene before and after changes may have occurred. We denote the initial image as the reference and the more recent as the current image. ...

Comparison of synthetic aperture sonar images and optical images of UXOs from the Skagerrak chemical munitions dumpsite

Hansen, Roy Edgar; Geilhufe, Marc; Bakken, Erik Makino; Sæbø, Torstein Olsmo (2019-11-28)

After World War II chemical munitions were loaded onto large ships and sunk in the Skagerrak Strait in the Norwegian trench, in deep waters between Norway and Denmark. In collaboration with the Norwegian Coastal Administration, ...

The Effect of Internal Wave-Related Features on Synthetic Aperture Sonar

Hansen, Roy Edgar; Lyons, Anthony P.; Sæbø, Torstein Olsmo; Callow, Hayden John; Cook, Daniel A. (2015)

In October 2012, the Centre for Maritime Research and Experimentation (CMRE, La Spezia, Italy) conducted trials from the NATO research vessel (RV) Alliance, off Elba Island, Italy. During this trial, data were collected ...

The impacts of scene stability and acoustic backscatter coherence on automated seabed change detection

Shouldice, Emma; Smith, Sonja; Sæbø, Torstein Olsmo; Crawford, Anna M; Midtgaard, Øivind; King, Jonathan; Johnson, Shawn F; Sternlicht, Daniel D.; Penko, Allison; Lyons, Anthony P.; Bakken, Erik Makino (2023-09)

Practical implementation of long-term seabed monitoring for civilian and military activities requires automated tools for detecting temporal seabed changes, such as for detection of new trawling activities or mine-like ...

Interferometric Synthetic Aperture Sonar in Pipeline Inspection

Hansen, Roy Edgar; Sæbø, Torstein Olsmo; Callow, Hayden John; Hagen, Per Espen (2010-10-14)

Accurate and reliable inspection of subsea pipelinestraditionally requires the use of multiple sensors, which againhave different requirements for range and geometry. This makespipeline inspection a time consuming and ...

Measurements of high-frequency acoustic scattering from glacially eroded rock outcrops

Olson, Derek R.; Lyons, Anthony P.; Sæbø, Torstein Olsmo (2016)

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 ...

A new approach to high-resolution seafloor mapping

Callow, Hayden John; Hagen, Per Espen; Hansen, Roy Edgar; Sæbø, Torstein Olsmo; Pedersen, Rolf B. (2012)

Optimising collection geometry for long-range synthetic aperture sonar interferometry

Hansen, Roy Edgar; Sæbø, Torstein Olsmo (2024-06-21)

Interferometric synthetic aperture sonar (SAS) is a technique to image and map theseabed in very high resolution. For large area coverage rate systems with hundreds ofmetres swath width, the achievable performance varies ...

Quantifying the negative impact of breaking internal waves on interferometric synthetic aperture sonar

Hansen, Roy Edgar; Lyons, Anthony P.; Cook, Daniel A.; Sæbø, Torstein Olsmo (2018)

The SENSOTEK Synthetic Aperture Sonar - results from HUGIN AUV trials

Hansen, Roy Edgar; Sæbø, Torstein Olsmo; Hayden, John Callow; Hagen, Per Espen (2007)

FFI har et samarbeid med Kongsberg Maritime for utvikling av syntetisk aperture sonar (SAS) teknologi for HUGIN autonom undervannsfarkost (AUV). Som en del av dette samarbeidet er en bredbåndet, bredstrålet interferometrisk ...

Spatial coherence of speckle for repeat-pass synthetic aperture sonar micronavigation

Synnes, Stig Asle Vaksvik; Hansen, Roy Edgar; Sæbø, Torstein Olsmo (2021-03-31)

Accurate positioning of autonomous underwater vehicles is a major challenge. The long-term drift is problematic if global position updates are not available, and for applications such as repeat-pass interferometry and ...

Synthetic aperture sonar images and bathymetries from the 2015 survey of the Skagerrak World War II Chemical Munitions Dump Site

Sæbø, Torstein Olsmo; Lorentzen, Ole Jacob (2016-03-16)

This report is a summary of the synthetic aperture sonar (SAS) processing results from the HUGIN HUS survey of the Skagerrak dump site in April 2015. The cruise was conducted from H. U. Sverdrup II for the Norwegian ...