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Now showing items 11-20 of 27
Low-Complexity Adaptive Sonar Imaging
(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 ...
Wideband Interferometry in Synthetic Aperture Sonar
(2013)
Synthetic aperture sonar (SAS) interferometry can provide very high resolution images and topographic maps of the seafloor over large swaths. Processing of interferometric data to retrieve reliable depth estimates of the ...
Comparison of synthetic aperture sonar images and optical images of UXOs from the Skagerrak chemical munitions dumpsite
(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, ...
Interferometric Synthetic Aperture Sonar in Pipeline Inspection
(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 ...
Detection of Point Scatterers in Medical Ultrasound
(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 ...
Multibeam Echosounder With Orthogonal Waveforms: Feasibility and Potential Benefits
(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. ...
Spatial coherence of speckle for repeat-pass synthetic aperture sonar micronavigation
(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 ...
Data-Driven Autocalibration for Swath Sonars
(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 ...