Browsing by Subject "Image processing"
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 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 neural-network-fusion architecture for automatic extraction of oceanographic features from satellite remote sensing imagery
(NATO. SACLANTCEN, 1999/06)This report describes an approach for automatic feature detection from fusion of remote sensing imagery using a combination of neural network architecture and the Dempster-Shafer (DS) theory of -
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 ... -
An automatic approach to ship detection in spaceborne synthetic aperture radar imagery: an assessment of ship detection capability using RADARSAT
(NATO. SACLANTCEN, 2000/12)This report describes a methodology for automated ship and wake detection in space-based synthetic aperture radar (SAR) imagery. The methodology incorporates a multistage approach involving several algorithms which can ... -
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 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 ... -
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 ... -
Joint probabilistic data association tracker for extended target tracking applied to X-band marine radar data
(CMRE, 2019/06)X-band marine radar systems are flexible and low-cost tools for monitoring multiple targets in a surveillance area. Although they may suffer from several sources of interference, e.g., sea clutter, they can provide ... -
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 ... -
Multi-look processing of high-resolution SAS data for improved target detection performance
(CMRE, 2019/06)The rich content of synthetic aperture sonar (SAS) data is typically used to generate imagery with resolution as high as theoretically possible. But when the ultimate purpose of the imagery is for detecting objects with ...