Browsing Reprints by Title
Now showing items 294-313 of 548
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Measurement and interpretation of angular spreading from multiple boundary interactions in a shallow water channel
(NATO. SACLANTCEN, 1997)The problem of angular spreading of sound that has undergone multiple boundary scattering (both sea surface and sea bed) in a shallow water channel is discussed. Measurements made of the horizontal spatial coherence along ... -
Measurement of the bubble population in coastal waters using combination frequencies of MHz order
(NATO. SACLANTCEN, 1997)This paper describes the use of a combinatron frequency technique to measure the size distribution of oceanic bubbles. Written between two sea trials, the paper describes how the apparatus cart be adapted to design tests ... -
Measurements and modelling of high-frequency acoustic scattering by a rough seafloor and sea surface
(NURC, 2009/12)Acoustic scattering by a rough, possibly dynamic interface is experimentally studied by insonifying the seabed and the sea surface at high frequency at various incidentangles. A directional source working at 300 kHz was ... -
Measurements of normal-mode amplitude functions in a nearly-stratified medium
(NATO. SACLANTCEN, 1975/10)In normal-mode treatments of acoustic propagation in nearly-stratified media, calculations are frequently based on the perfectly-stratified medium model, in which symmetry permits separation of the wave equationo In these ... -
Medium-induced low-frequency fluctuations in acoustic transmission loss: examples from measurements in selected geographical areas
(NATO. SACLANTCEN, 1986/06)The ocean is a complex, highly variable acoustic nedium. A propagating acoustic signal is affected by a host of phenomena, including the sea-surf ace and bottom, volume inhomogenei ties, internal waves and tides, and ... -
Methods used in France for the calculation of sound fields
(NATO. SACLANTCEN, 1971/12) -
METOC-driven Vessel Interdiction System (MVIS): supporting decision making in Command and Control (C2) systems
(CMRE, 2019/06)This paper presents a decision support system (DSS) to help Command and Control (C2) operators. Hereby, the METOC-driven vessel interdiction system (MVIS) is presented. It is aimed to help the decision-making process in ... -
Micro-bathymetry data acquisition for 3D reconstruction of objects on the sea floor
(CMRE, 2019/06)This paper describes an effort to capture micro-bathymetry data for the end purpose of 3D object reconstruction, using an AUV-borne multibeam echo sounder. Due to the combination of relatively narrow across-track coverage ... -
Mining maritime vessel traffic: promises, challenges, techniques
(CMRE, 2019/06)This paper discusses machine learning and data mining approaches to analyzing maritime vessel traffic based on the Automated Information System (AIS). We review recent efforts to apply machine learning techniques to AIS ... -
Mobile range for measuring ship radiated acoustic noise
(NATO. SACLANTCEN, 1985/01)The Mobile Range described in this paper allows measurements of noise radiated from both surface ships and submarines in open seas with bottom depths from less than lOOm to 400 meters. The range is being developed and built ... -
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 ...