Browsing CMRE Publications by Type "Papers and Articles"
Now showing items 161-180 of 562
-
Deep-sea circulation in the Alboran sea
(NATO. SACLANTCEN, 1985/04)Alboran Sea circulation between 220 and 1100 m depth is studied. Interaction between three types of water masses in this area causes a complicated flow pattern. Atlantic water flowing as a jet through the Strait of Gibraltar ... -
Delay-Doppler resolution performance of large time-bandwidth product linear FM signals in a multi- path ocean environment
(NATO. SACLANTCEN, 1989/04)Active sonar systems that transmit large time-bandwidth (TW)-product linear frequency modulated (LFM) waveforms and receive echoes from targets of unknow~r~an ge and speed can suffer considerable correlation losses that ... -
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 ... -
Deployment of a persistent underwater acoustic sensor network: the CommsNet17 experience
(CMRE, 2019/05)This paper presents the experimental activities performed by the NATO STO Centre for Maritime Research and Experimentation (CMRE) during the CommsNet17 trial where a persistent Underwater Acoustic Sensor Network (UASN) was ... -
Depth dependence of directionality of ambient noise in the North Pacific: experimental data and equipment design
(NATO. SACLANTCEN, 1982/06)Ambient ocean noise studies have been part of the research program of the Marine Physical Lab (MPL) for many years. In recent years this work has included several studies of the depth dependence of vertical directionality ... -
Design of synthetic aperture sonar systems for high-resolution seabed imaging (tutorial slides)
(NURC, 2006/10)This tutorial reviews the key aspects of the design of synthetic aperture sonar (SAS) systems for -
Detecting anomalous deviations from standard maritime routes using the Ornstein-Uhlenbeck process
(CMRE, 2019/05)A novel anomaly detection procedure based on the Ornstein-Uhlenbeck (OU) mean-reverting stochastic process is presented. The considered anomaly is a vessel that deviates from a planned route, changing its nominal velocity ... -
Detection models and target information processing
(NATO. SACLANTCEN, 1982/06)The passive sonar equation leads in a natural manner to sensor detection performance contours. Useful information can be extracted from observed fractional holding time on non-cooperative targets by use of these contours. ... -
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 ... -
Detection, tracking and fusion of multiple HFSW radars for ship traffic surveillance: experimental performance assessment
(CMRE, 2014/05)Low-power HF surface-wave radars fit well the role of long-range early-warning tools in maritime situational awareness applications, by virtue of their over-the-horizon coverage capability and continuoustime mode of ... -
Determination of velocity profile and sea bed characteristics from high frequency pulse propagation in a shallow water Mediterranean environment
(NATO. SACLANTCEN, 1997)Time-domain features of shallow water Mediterranean and Yellow Sea data are simulated for frequency band widths of 0.8 kHz with a centralfrequency of 3.2 kHz. Contour plots of pulse arrivals in time and depth are analyzed ... -
Deterministic methods of sound field computation
(NATO. SACLANTCEN, 1975/10)Models for acoustic propagation in the ocean environment have matured to a level where they are used routinely to estimate deterministic phenomena and, most recently, have been applied to the investigation of stochastic ... -
Deterministic propagation modelling: Part 1: Fundamental principles *Part 2: Numerical results
(NATO. SACLANTCEN, 1981/06)The physics of sound propagation in the ocean is briefly reviewed. The wave equation is presented and a set of solutions under a variety of approximations is discussed. The consistency among these solutions is illustrated. -
Development of a software-defined and cognitive communications architecture at CMRE
(2019/05)This paper presents an overview of the functionalities of the Cognitive Communications Architecture (CCA) that is currently under development at the NATO Science and Technology Organisation (STO) Centre for Maritime Research ... -
Development of military ARGUS computers and MOD bus for close-coupled signal processing applications
(NATO. SACLANTCEN, 1979/12)The next generation of Naval sonar systems will make extensive use of flexible programable modules to implement signal-processing algorithms. A number of UK Defence Establishments are engaged in a series of coordinated ... -
Different approaches to economic cruising speeds on a CODOG frigate with due regard to radiated noise
(NATO. SACLANTCEN, 1985/01)All navies, in recent years, have been much more concerned in economic cruising speeds of ships. Frigate type naval ships are usually characterized by two shafts, by multiple propulsion engines per shaft, and by different ... -
Digital acoustical processing at Woods Hole Oceanographic Institution
(NATO. SACLANTCEN, 1972/05) -
Digital signal processing of high resolution within-pulse sector scanning sonars
(NATO. SACLANTCEN, 1979/12)The characteristics of three scanning sonars, presently in use at the Admiralty Marine Technology Establishment, and operating at frequencies of 300kHz, 150kHz and 75kHz are described. The performance of a system for ... -
Directional measurements of low-frequency acoustic backscattering from the seafloor
(NATO. SACLANTCEN, 1986/06)Long-range, low-frequency directional measurements of acoustic backscattering from the seafloor were made in the Tyrrhenian Sea using explosi ve sound sources. The signals were received by a horizontal towed array of ...