Browsing by Subject "Sonar images"
Now showing items 1-20 of 35
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3D target shape from SAS images based on a deformable mesh
(NURC, 2009/12)The seafloor can nowadays be scanned with side-looking sonar that provides a very high resolution over a large swath, which has proved beneficial for underwater target detection and classification. For systems operated at ... -
A high frequency approach for seabed vegetation characterization
(NATO. SACLANTCEN, 1997)This paper focuses on the characterization of seabed vegetation, an interesting problem in a lot of Mediterranean sea coastal sites since water quality and pollution degree can be efficaciously solved by investigating the ... -
A method for the three-dimensional reconstruction of underwater objects
(NATO. SACLANTCEN, 1996/10)This report describes a method to estimate the three-dimensional aspects of underwater objects using a sequence of sonar images. The data are recorded by a sector scanning sonar, carried by an underwater vehicle which ... -
A new ambient noise imaging system for ANI, passive and bistatic active acoustic imaging in shallow water
(NATO. SACLANTCEN, 1997)Shallow water active and passive sonars can be usefully complimented by broadband Ambient Noise Imaging (ANI) systems. The first AN1 system was largely analogue, produced good images at 38 m range, but was bulky and permitted ... -
Active contours for synthetic aperture sonar snippet registration
(CMRE, 2019/06)In mine-hunting operations, there is currently a strong focus on using autonomous systems in order to remove personnel and ships from the minefield. These systems must perform their missions effectively, and the collected ... -
Analysis and problems of HF acoustic coherent and incoherent simulations in shallow water
(NATO. SACLANTCEN, 1997)Shallow water environments create complex scattering condit~ons due to the sea surface and bottom scattering mechanisms. An analysis of the effects of the scattering mechan~smso n sonar images of simple targets in shallow ... -
Autofocusing a synthetic aperture sonar using the temporal and spatial coherence of seafloor reverberation
(NATO. SACLANTCEN, 1997)An autofocusing algorithm for the compensation of translational motion errors of a sea floor rmaging synthetic aperture side scan sonar is presented. The algorithm does not depend on the presence or absence of dominant ... -
AUV-enabled adaptive underwater surveying for optimal data collection
(NURC, 2012/04)A new adaptive strategy for performing data collection with a sonar-equipped autonomous underwater vehicle (AUV) is proposed. The approach is general in the sense that it is applicable to a wide range of underwater tasks ... -
Bayesian inference and sidescan restoration
(NATO. SACLANTCEN, 1997)We consider a Bayesian approach to the problem of inferring parameters of the SONAR environment given only the gathered sidescan image. A simplified model of the process is developed along with suitable distributions on ... -
Demystifying deep convolutional neural networks for sonar image classification
(CMRE, 2019/06)Deep convolutional neural networks (CNNs) are developed to perform underwater target classification in synthetic aperture sonar (SAS) imagery. The deep networks are trained using a huge database of sonar data collected at ... -
Detection of objects on a non Rayleigh background
(NATO. SACLANTCEN, 1995/12)Sector scanning sonar systems image the sea-bottom to detect objects that can be distinguished from the background structure of the seabottom. In current systems images are displayed and discarded as new image data become ... -
Detection rate statistics in synthetic aperture sonar images
(NURC, 2009/12)Synthetic aperture sonar (SAS) has proved to be successful for mine hunting andis now robust for generating high-resolution images over wide swath. The subsequent stepin the processing is detection, discriminating between ... -
Estimating surface orientation from sonar images
(NATO. SACLANTCEN, 1997)A maximum likelihood method for estimating remote surface orientation from multi-static sonar images is presented. It is assumed that the sonar images are corrupted by signal-dependent noise, known as speckle, arising from ... -
Exploiting phase information in synthetic aperture sonar images for target classification
(CMRE, 2019/05)It is demonstrated that the phase information present in complex high-frequency synthetic aperture sonar (SAS) imagery can be exploited for successful object classification. That is, without using the amplitude content of ... -
Fast unsupervised seafloor characterization in sonar imagery using lacunarity
(CMRE, 2019/06)A new unsupervised approach for characterizing seafloor in side-looking sonar imagery is proposed. The approach is based on lacunarity, which measures the pixel-intensity variation, of through-the-sensor data. No training ... -
Forward looking sonar mosaicing for mine countermeasures
(CMRE, 2019/06)Forward looking sonars (FLS) are nowadays popular for many different applications. In particular, they can be used for Automatic Target Recognition (ATR) in the context of Mine Countermeasures. Currently, ATR techniques ... -
High resolution sonar (tutorial slides)
(NURC, 2010/07) -
Interactive tools for the exploration and analysis of multibeam and other seafloor acoustic data
(NATO. SACLANTCEN, 1997)The Ocean Mapping Group has developed a full suite of software tools for the real-time or near real-time display, editing, quality control, interpretation and visualization of multibeam sonar data. The combination of ... -
Interpretation and fusion of sonar images using evidential reasoning
(NATO. SACLANTCEN, 1995/12)A method and system architecture for automatic interpretation and fusion of multiple sonar images is proposed. The interpretation of a sonar image consists of the creation of a symbolic geographical map indicating the ... -
The Mondrian detection algorithm for sonar imagery
(CMRE, 2019/06)A new algorithm called the Mondrian detector has been developed for object detection in high-frequency synthetic aperture sonar (SAS) imagery. If a second (low) frequency-band image is available, the algorithm can seamlessly ...