Browsing by Title
Now showing items 477-496 of 882
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Mechanisms for subcritical penetration into a sandy bottom: experimental and modelling results
(NATO. SACLANTCEN, 1998/05)This paper presents the results of a recent study whose overall objectives are to determine the mechanism(s) contributing to subcritical acoustic penetration into ocean sediments, and to quantify the results for use in ... -
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 ... -
Mixed layer deepening and variability in the upperlayers if the central western Mediterranean, MILEX-82: final report
(NATO. SACLANTCEN, 1988/10)The 1982 Mixed-Layer Experiment (MILEX-82) is described in detail and the data are presented in ways designed to illustrate the spatial and temporal variability of the surface and deeper layers of the central western ... -
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 ... -
Mode and PE predictions of propagation in range-dependent environments: SWAM'99 workshop results
(NATO. SACLANTCEN, 2000/05)Three numerical acoustic models, a coupled normal-mode model (C-SNAP), -
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 statistics of inertial shear from multi- year simulations at weathership 'Mike': currents, atmospheric forcing, internal waves, mixed layer, Norwegian Sea)
(NATO. SACLANTCEN, 1990/12)In this memorandum we focus on one of the most important environmental -
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 non-Rayleigh reverberation
(NATO. SACLANTCEN, 1997/05)Researchers over the past three decades have experimentally examined non-Rayleigh reverberation, -
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 ... -
Modelling acousto-elastic waveguide/object scattering with the Rayleigh hypothesis
(NATO. SACLANTCEN, 1998/06)In this memorandum the plane wave scattering matrices for a range-dependent seabed and upper free surface are computed using the -
Modelling of scattering by objects on the seabed
(NATO. SACLANTCEN, 1997/12)This paper describes some of the theory and implementation issues of modeling the backscattered -
Modelling of scattering by partially buried elastic cylinders
(NATO. SACLANTCEN, 1998/02)The work of a previous memorandum on the modelling of scattering by a partially buried cylinder is extended to allow the cylinder to have full elasticity (and not just be a fluid structure as in the previous work). The ...