Browsing Technical Reports by Title
Now showing items 270-289 of 322
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Statistical normalization of non-Rayleigh reverberation
(NATO. SACLANTCEN, 2000/02)Low-frequency active sonar systems operating in shallow water are primarily limited by reverberation. -
Studies on information mechanics
(NATO. SACLANTCEN, 1987/04)Related issues connected with the transmission of information in a command and control environment -
Sub-sea floor buried reflectors imaged by low frequency active sonar
(NATO. SACLANTCEN, 1996/06)Low Frequency Active Sonar (LFAS) utilizes low-frequency acoustic -
SUPREMO: a multistatic sonar performance model
(NATO. SACLANTCEN, 2002/11)Multistatic sonars introduce new problems to the modeller such as mutual interference from multiple sources and variable target aspect in a background of range-dependent bistatic reverberation. A multistatic sonar performance ... -
Surface measurements made during the Icelandic Current Experiment (ICE 89) from the R/V Alliance
(NATO. SACLANTCEN, 1991/10)Measurements of surface meteorology and sea temperature taken during the GIN '89A cruise of the research vessel Alliance are presented in the form of time-series plots. The cruise was in the southern Icelandic and Norwegian ... -
Surface measurements made from the R/V ALLIANCE during the Mediterranean aircraft-ship transmission experiment (MASTEX), June 1990
(NATO. SACLANTCEN, 1992/12)Measurements of sea-surface temperature, surface meteorology and atmospheric profiles taken during the June 1990 cruise of the R/V Alliance in the Aegean and Ionian Seas are presented in graphical form. True winds, net ... -
Target detection using a three-layered neural network trained by supervised back-propagation
(NATO. SACLANTCEN, 1990/05)In any sonar system a detection process has to be performed at -
Target localization with multiple sonar receivers
(NATO. SACLANTCEN, 2000/01)Deployable Underwater Surveillance Systems (DUSS) are a network of small multistatic transmitter/receiver sonar nodes. This study analyzes the contact localization capabilities of DUSS in term of range, time and bearing ... -
Target motion effects on passive sonar: an appraisal of basic factors
(NATO. SACLANTCEN, 1986/12)Detection and tracking by passive sonar involve the observation of the target-radiated noise in bearing-cells and time-cells that have their dimensions predetermined by a combination of physical limitations, e.g. the size ... -
Temporal and spatial variabilities in shallow water acoustics: measurements and predictions
(NATO. SACLANTCEN, 1985/03)An acoustic signal propagating in the sea is generally degraded not only by interactions with the bottom and surface boundaries, but also by volume inhomogeneities caused by non-uniformities in temperature, density, and ... -
Test and evaluation of objective mapping applied to oceanographic data from GIN Sea'86
(NATO. SACLANTCEN, 1989/03)This study is an investigation to produce an objective analysis -
Testing finite differencing schemes for the shallow water equations
(NATO. SACLANTCEN, 1987/10)The explicit, the semi-implicit, and the fractional step schemes are tested and compared in the -
The application of coupled-mode theory to propagation in shallow water with randomly varying sound speed
(NATO. SACLANTCEN, 1987/06)Sound propagation in the Baltic Sea cannot be described correctly by range independent propagation -
The application of parametric side scan sonar to the detection of proud and buried targets
(NATO. SACLANTCEN, 1998/01)This paper describes an experiment designed to evaluate the feasibility of using the TOPAS parametric transmitter mounted in side scan mode, for the detection of buried targets. The concept was tested with proud targets ... -
The application of spread-spectrum communications to REA tactical networks and deployable underwater surveillance systems
(NATO. SACLANTCEN, 1999/08)The present document is a part of an ongoing study on advanced communication techniques in support of Rapid Environmental Assessment (REA) and Deployable Undersea Surveillance Systems (DUSS). It aims at the definition of ... -
The Barny program: fourteen years of NURC-NRL collaboration
(NURC, 2009/05)Shallow ocean environments, with their rapid variability, short spatial scales and often intense fishing, pose a special challenge for physical oceanographic study. Since 1995, a series of collaborative programs between ... -
The characterization of a range-dependent environment using towed horizontal array data from the MAPEX 2000 experiment
(NATO. SACLANTCEN, 2002/11)The characterization of ocean environments using geoacoustic inversion techniques has received a -
The determination of permeability in in-situ marine-floor sediments
(NATO. SACLANTCEN, 1985/11)A method of evaluating in situ permeability of unconsolidated marine floor sediments has been -
The effect of a layer of varying density on high-frequency acoustic reflection, forward propagation loss and backscattering strength
(NATO. SACLANTCEN, 1997/06)This report examines the impact that a thin layer of varying density would have on high-frequency reflection, forward loss and backscattering of acoustic plane waves from the seafloor. A functional form for density ... -
The effect of thermohaline variability on the exchange through Mediterranean straits
(NATO. SACLANTCEN, 1989/05)exchanges through straits. The primary assumption is that the exchange is determined by tlle pressure force created by the differing weights of tlle water columns on either side of the sill and by the continuity of mass ...