Browsing Reprints by Title
Now showing items 304-323 of 548
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Model for the frequency spread of backscattered underwater sound based on the facet model of the rough sea surface
(NATO. SACLANTCEN, 1978/11)A theoretical model for the doppler spread of backscattered acoustic waves from the rough sea surface is described on the basis of the decomposition of the continuous sea-surface spectrum that leads to the concept of facets. ... -
Model performance assessment for long-term vessel prediction using HFSW radar data
(CMRE, 2019/06)Vessels in open seas are seldom continuously observed. Thus, the problem of long-term vessel prediction becomes crucial. This paper focuses its attention on the performance assessment of the Ornstein- Uhlenbeck target ... -
Model-aided data adaptive suppression of reverberation
(NATO. SACLANTCEN, 1993/08)We propose a processing methodology which is based on the piece-wise modeling, adaptive estimation, and removal of reverberation components. An important feature of this approach is that backscatter models and information ... -
Modeling of subcritical penetration into sediments due to interface roughness
(NATO. SACLANTCEN, 1997)Recent experimental results reveal acoustic penetration into sandy sediments at grazing angles below the critical angle. We have been investigating a mechanism for subcritical penetration based on scattering at a rough ... -
Modeling range-dependent, high-frequency, shallow-water torpedo reverberation data
(NATO. SACLANTCEN, 1997)The high-frequency, forward bottom losses predicted by a lossy Rayleigh and a Biot poroelastic sediment model are substantially different. These differences will accumulate and become measurable in multiple bottom bounce ... -
Modeling vessel kinematics using a stochastic mean-reverting process for a long-term prediction
(CMRE, 2019/06)We present a novel method for predicting long-term target states based on mean-reverting stochastic processes. We use the Ornstein-Uhlenbeck (OU) process, leading to a revised target state equation and to a time scaling ... -
A modem design for underwater acoustic networking in the High North
(CMRE, 2019/05)We design a software modem for long range underwater acoustic communications in ice-covered oceans. The modem is equipped with three coded modulation schemes achieving 1.8, 21.4 and 96.2 bps, respectively. In addition, we ... -
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 ... -
Moving JANUS forward: a look into the future of underwater communications interoperability
(CMRE, 2017/11)In the past 8 years, the Centre for Maritime Research and Experimentation (CMRE) has developed, tested and promoted JANUS - a robust and simple modulation and coding scheme to be used as the first standard to support ... -
Multi-criteria weather routing optimization based on ship navigation resistance, risk and travel time
(CMRE, 2019/05)This paper presents the analysis of the weather routing scenario in a multi-criteria setup. The set of 3 conflicting criteria is: added navigation resistance (caused by wind and waves), navigation risk and travel time. To ... -
Multi-domain robotics competitions: the CMRE experience from SAUC-E to the European Robotics League Emergency Robots
(CMRE, 2019/06)This paper details the experience of the Centre for Maritime Research and Experimentation (CMRE) in the organisation of several robotics competitions since 2010. In particular, the Student Autonomous Underwater Vehicle ... -
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 ... -
Multi-sensor data acquisition, tracking, fusion and intelligent decision aids in the NATO Maritime Situational Awareness Initiative: countering underwater intruders
(NURC, 2007/10)The objective of the NATO Maritime -
Multi-sensor ISAR technique for translational motion estimation
(CMRE, 2019/06)In the last years a lot of interest has grown concerning the exploitation of data acquired by multiple sensors belonging to multistatic or Multiple Input Multiple Output systems. Indeed increased information and/or better ... -
Multi-view SAS image classification using deep learning
(CMRE, 2017/11)A new approach is proposed for multi-view classification when sonar data is in the form of imagery and each object has been viewed an arbitrary number of times. An image-fusion technique is employed in conjunction with a ... -
Multi-view target classification in synthetic aperture sonar imagery
(NURC, 2009/12)This work proposes an elegantly simple solution to the general task of classifying the shape of an object that has been viewed multiple times. Specifically, this problem is addressed in the context of underwater mine ... -
Multi-waveform active sonar tracking
(NURC, 2007/06)This paper extends the NURC distributed multihypothesis -
Multipath field representation for seabed parameter extraction using backscatter data from shadow zones
(NATO. SACLANTCEN, 1997)Inversion strategies for bottom parameter estimation in shallow water impose stringent requirements on accuracy and speed of acoustic models. We highlight the importance of second order effects as first order determinants ... -
Multipath pulse shape in a refracting environment
(NURC, 2007/11)Multiple boundary interactions in shallow water propagation introduce a more or less Gaussian angle distribution at a distant receiver. When all paths are added the result is 'mode-stripping', i.e. the steep rays are ... -
Multipath pulse shapes in shallow water: theory and simulation
(NURC, 2007/04)In shallow water propagation the steeper ray angles are weakened most by boundary losses. Regarding the sound intensity as a continuous function of angle it can be converted into a function of travel time to reveal the ...