Browsing CMRE Publications by Title
Now showing items 320-339 of 882
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Efficient dense sonar surveys with an autonomous underwater vehicle
(CMRE, 2014/01)An algorithm for the in situ adaptation of the survey route of an autonomous underwater vehicle (AUV) equipped with side-looking sonars was recently proposed. This algorithm immediately exploits the through-the-sensor data ... -
Efficient global matrix approach to the computation of synthetic seismograms
(NATO. SACLANTCEN, 1986/05)A numerically efficient global matrix approach to the solution of the wave equation in horizontally stratified environments is presented. The field in each layer is expressed as a superposition of the field produced by the ... -
EM phenomena in the ELF range: EM fields of submerged dipoles and finite antennas
(NATO. SACLANTCEN, 1965/06)The report is the first of a series of three that discusses various EM phenomena in the ELF range. The expressions for the various components of the EM field from submerged dipoles are presented. Although similar expressions ... -
EM phenomena in the ELF range: natural background noise and instrumentation for its measurement
(NATO. SACLANTCEN, 1965/06)The report is the second of a series of three that discusses various EM phenomena in the ELF range. A general outline of the natural background noise in the frequency range between 1 and 50 cps is given and the measurement ... -
Environmental field estimation by consensus based dynamic sensor networks and underwater gliders
(CMRE, 2019/06)A coordinated dynamic sensor network of autonomous underwater gliders to estimate 3D time-varying environmental fields is proposed and tested. Each sensor performs local Kalman filter sequential field estimation. A network ... -
Environmental impact on mobile sonar shallow water operations
(NATO. SACLANTCEN, 1993/08)Shallow Water operations provide unique challenges for mobile sonars. In many cases propagation conditions can be optimized - our studies have shown that sound channeling can occur in approximately 75% of the strategic ... -
Estimating surface orientation from sonar images
(NATO. SACLANTCEN, 1997)A maximum likelihood method for estimating remote surface orientation from multi-static sonar images is presented. It is assumed that the sonar images are corrupted by signal-dependent noise, known as speckle, arising from ... -
Estimation of chirp sonar signal attenuation for classification of marine sediments: improved spectral ratio method
(NATO. SACLANTCEN, 1997)Remote sediment classification through acoustic methods is of great interest for a few years. The attenuation coefficient of the transmitted wave is an important feature to characterize physical sediment layers properties. ... -
Estimation of shear wave properties in the upper sea-bed using seismo-acoustical interface waves
(NATO. SACLANTCEN, 1997)Acoustic interface waves have been recorded with a bottom deployed acoustic array at several locations. High resolution array processing technique (Prony) is used to estimate velocity versus frequency for the interface ... -
Estimators for model-based passive localization
(NATO. SACLANTCEN, 1988/07)A comparative study is made of the performance of four different estimators as used in the matched field technique of passive localization. The study is based on both real and synthesized data. In the synthesized data case, ... -
The euRathlon 2015 Grand Challenge: the first outdoor multi-domain search and rescue robotics competition - a marine perspective
(CMRE, 2019/06)The euRathlon project was an FP7-funded Coordination and Support Action (2013-2015). Its main aim was to organize outdoor robotics competitions in realistic search and rescue response scenarios for cooperative land, sea, ... -
EVA - an evaluator of vague evidence in ASW situations: an expert system prototype
(NATO. SACLANTCEN, 1987/10)This paper presents an example of how an expert system can contribute to the creation and updating -
Evaluation of experimental techniques for determining the plane wave reflection coefficient at the sea floor
(NATO. SACLANTCEN, 1986/06)One of the most commonly used techniques for determinati on of the geoacoustical properties of the sea bed is the measurement of plane wave reflection coefficients at the ocean bottom. An incident field is pr oduced by ... -
Evaluation of low-frequency bottom backscattering strength vs grazing angle by means of multiple beamforming
(NATO. SACLANTCEN, 1986/06)Bottom backscattering strength was measured in deep water as a function of grazing angle in the Balearic Abyssal Plain of the Mediterranean. The measurements were made with a towed, narrowband low-frequency omnidirectional ... -
Experience with a MAP 300 array processor
(NATO. SACLANTCEN, 1979/12)The paper is a summary of the experience collected during almost two years of programming a CSPI MAP 300 array ' processor in signal processing applications. After a short overview of the most interesting features of SNAP ... -
Experimental data on the refraction of underwater explosion pulses
(NATO. SACLANTCEN, 1971/12)There are several reasons why a researcher in underwater acoustics might be interested in the use of explosion pulses as sources. The most generally recognized reason is that explosions are convenient and powerful sources ... -
Experimental demonstration of the focused acoustic field in the ocean
(NATO. SACLANTCEN, 1998/10)An experiment conducted in the Mediterranean Sea in April1996 demonstrated that a time reversal mirror (or phase conjugate array) can be implemented to spatially and temporally refocus an incident acoustic field back to ... -
Experimental evaluation of Net-LBL: an acoustic network-based navigation system
(CMRE, 2019/06)This paper describes the use and in-field evaluation of a Networked-Long Base Line system (Net-LBL) where a network of underwater nodes cooperate to support the localisation and navigation of mobile vehicles. To avoid the ... -
Experimental results of 300 kHz shallow water synthetic aperture sonar
(NURC, 2007/11)The design of a shallow water synthetic aperture sonar (SAS) requires an understanding of key system and environmental issues. The main factors which limit SAS performance are micronavigation accuracy, where micronavigation ... -
Experiments with multi-vehicle operations: the Rapid Environmental Picture Atlantic exercise 2014
(CMRE, 2019/06)The paper describes the Rapid Environmental Picture Atlantic exercise 2014 (REP14-Atlantic), with special focus on the experiments with autonomous underwater, surface and air vehicles, and discusses how large scale ...