Now showing items 1-10 of 10

    • 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 ...
    • Bayesian seabed classification using angle-dependent backscatter data from multibeam echo sounders 

      Landmark, Knut; Solberg, Anne H Schistad; Austeng, Andreas; Hansen, Roy Edgar (2014)
      Acoustical seabed classification is a technology for mapping seabed sediments. Processed multibeam sonar data yield the variation of the seabed scattering strength with incidence angle, and this paper examines the effect ...
    • Data-Driven Autocalibration for Swath Sonars 

      Lønmo, Tor Inge Birkenes; Austeng, Andreas; Hansen, Roy Edgar (2020-12-20)
      Sidelobes in swath sonar water column imagery can obscure targets of interest and create erroneous bottom detections. Differences between ideal and actual element responses limit the achievable sidelobe level for practical ...
    • Detection of Point Scatterers in Medical Ultrasound 

      Thon, Stine Hverven; Hansen, Roy Edgar; Austeng, Andreas (2021-11-19)
      We present an overview of the detection of point scatterers in ultrasound images and suggest strategies for evaluating and measuring the detection performance. We use synthetic aperture Field II simulations of a point ...
    • Interference rejection for sonars via low,complexity adaptive beamforming 

      Lønmo, Tor Inge Birkenes; Austeng, Andreas; Hansen, Roy Edgar (2015)
    • Low-Complexity Adaptive Sonar Imaging 

      Buskenes, Jo Inge; Hansen, Roy Edgar; Austeng, Andreas (2016)
      We have studied the low-complexity adaptive (LCA) beamformer in active sonar imaging. LCA can be viewed as either a simplification of the minimum variance distortionless response (MVDR) beamformer, or as an adaptive extension ...
    • Multibeam Echosounder With Orthogonal Waveforms: Feasibility and Potential Benefits 

      Blachet, Antoine; Austeng, Andreas; Aparicio, Joaquin; Hunter, Alan Joseph; Hansen, Roy Edgar (2021-04-15)
      Modern multibeam echosounders (MBE) employ frequency-division techniques (FDT) to ensonify multiple sectors within the same ping cycle. This leads to improved performance in coverage rate, and yaw and pitch stabilization. ...
    • Point detection in textured ultrasound images 

      Thon, Stine Hverven; Austeng, Andreas; Hansen, Roy Edgar (2023-02-26)
      Detection of point scatterers in textured ultrasound images can be challenging. This paper investigates how four multilook methods can improve the detection. We analyze many images with known point scatterer locations and ...
    • A Radon-Transform-Based Image Noise Filter - With Applications to Multibeam Bathymetry 

      Landmark, Knut; Solberg, Anne H Schistad; Albregtsen, Fritz; Austeng, Andreas; Hansen, Roy Edgar (2015)
      This paper describes a linear-image-transform-based algorithm for reducing stripe noise, track line artifacts, and motion-induced errors in remote sensing data. Developed for multibeam bathymetry (MB), the method has also ...
    • Wideband Synthetic Aperture Sonar Back Projection with Maximization of Wave Number Domain Support 

      Synnes, Stig Asle Vaksvik; Hunter, Alan Joseph; Hansen, Roy Edgar; Sæbø, Torstein Olsmo; Callow, Hayden John; Van Vossen, Robbert; Austeng, Andreas (2017)
      Wideband and widebeam synthetic aperture sonar (SAS) can provide information on the frequency- and aspect-dependent scattering in a scene. We suggest an approach to predict the quality of the sensor data over the available ...