Browsing Reprints by Title
Now showing items 529-548 of 548
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Underwater photography for quantitative description of bottom roughness
(NATO. SACLANTCEN, 1985/04)Knowledge of the roughness of the sea floor is obviously of great importance in marine geology for understanding the processes of the ocean bottom, and in underwater acoustics for understanding the scattering process. The ... -
Underwater source localization using a hydrophone-equipped glider
(CMRE, 2014/01)Buoyancy-driven underwater gliders are autonomous underwater vehicles that were originally developed to collect oceanographic data. CMRE is studying the use of this technology for the characterization of denied areas, ... -
Underwater target classification in synthetic aperture sonar imagery using deep convolutional neural networks
(CMRE, 2019/06)Deep convolutional neural networks are used to perform underwater target classification in synthetic aperture sonar (SAS) imagery. The deep networks are learned using a massive database of real, measured sonar data collected ... -
Uniqueness problems in extracting environmental parameters from high-frequency shallow-water reverberation measurements
(NATO. SACLANTCEN, 1997)Inversion techniques that extract environmental parameters from measured reverberation often lead to mathematical problems that are not well-posed. Two examples illustrate this possibility. The first hows how a model can ... -
Unmanned surface vessels for surface and subsurface threats in harbours: background and practical lessons
(NURC, 2009/12)The use of Unmanned Surface Vehicles (USVs) in harbour protection missions has been studied through technology surveys and experimentation within the programme of work at NURC. The crucial subsystems and vehicle payloads ... -
Use of the towship for assessing towed-array performance and analyzing data quality
(NATO. SACLANTCEN, 1982/11)A series of relatively simple tests are presented and discussed, which used in conjunction with the noise received from the towship, can be used in real time to assess the performance of a towed array and the quality of ... -
User-orientated software for signal analysis
(NATO. SACLANTCEN, 1979/12)A conflict exists between dedicated analysis instruments which are easy to use but inflexible and general purpose computers which are adaptable but require program development. A software package has been. developed which ... -
Using intelligent graphics terminals in real-time processing
(NATO. SACLANTCEN, 1979/12)At the Naval Research Laboratory intelligent graphics terminals are being utilized for real-time acquisition, storage, processing and display of oceanographic data when mini-computer systems are inappropriate. The intelligent ... -
Validation of the Ornstein-Uhlenbeck route propagation model in the Mediterranean Sea
(CMRE, 2019/06)Traffic route analysis and prediction are both crucial to maritime security. The ability to predict a vessel position in the future is essential to provide information on upcoming events. However, accurate prediction along ... -
Variability in the Gulf of Cadiz: internal waves and globs
(NATO. SACLANTCEN, 1980/08)An experiment was performed in the Gulf of Cadiz during June 1977, with the objective of separating oceanic variability due to internal waves from that due to inhomogeneities of the water. A CTD which oscillates in depth ... -
Variable sea level and strait flows in the Mediterranean: a theoretical study of the response to meteorological forcing
(NATO. SACLANTCEN, 1983/05)Changes in atmospheric pressure over the Mediterranean are thought to account for a significant part of low frequency sea level changes and associated flow through the Strait of Gibraltar. However, Crepon's (1965) examination ... -
Variable structure interacting multiple model algorithm for ship tracking using HF surface wave radar data
(CMRE, 2019/06)These last decades spawned a great interest towards low-power High-Frequency (HF) Surface-Wave (SW) radars for ocean remote sensing. By virtue of their over-the-horizon coverage capability and continuous time mode of ... -
A verification, validation and accreditation process for autonomous interoperable systems
(CMRE, 2019/05)Navies, Industries and Research are investigating how to move to future mine counter measure operations where of multiple autonomous underwater vehicles work collaboratively with minimal human interaction. Modelling and ... -
Vertical porosity and velocity fluctuations in shallow-water surficial sediments and their use in modeling volume scattering
(NATO. SACLANTCEN, 1997)Variability in sediment porosity and velocity creates volume scattering which is a parameter used in high-frequency scattering models. High-resolution vertical profiles of sediment porosity and compresstonal wave velocity ... -
Very-high (cm scale) resolution multichannel seismology
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Vessel pattern knowledge discovery from AIS data: a framework for anomaly detection and route prediction
(CMRE, 2014/01)Understanding maritime traffic patterns is key to Maritime Situational Awareness applications, in particular, to classify and predict activities. Facilitated by the recent build-up of terrestrial networks and satellite ... -
Volumetric distribution of oceanographic fields estimated from remote sensing and in situ observations from autonomous underwater vehicles of opportunity
(NURC, 2012/04)A main challenge of military oceanography (MILOC) is to assess the oceanographic conditions of denied/highrisk marine regions. Monitoring technologies are limited to those that can provide access to these regions. Remote ... -
Wavefront curvature ranging as a passive synthetic aperture problem
(NATO. SACLANTCEN, 1997)A new method of wavefront curvature passive ranging is introduced that is based on a model-based approach. The signal and measurement systems are placed into state-space form, thereby allowing the unknown parameters of the ... -
Wavelet analysis of side scan sonar imagery for classification
(NATO. SACLANTCEN, 1997)Wavelet-based techniques are presented for compressing side scan sonar images communicated from UUV's through band limited communication channels. Testing with an automatrc classifier on reconstructed images demonstrates ... -
Weather-routing system based on METOC navigation risk assessment
(CMRE, 2019/05)This paper presents a novel weather-routing system based on a multi-criteria setup. The set of 3 conflicting criteria is: travel time, ship navigation added resistance (caused by wind and waves), and navigation risk/safety. ...