Browsing CMRE Publications by Title
Now showing items 773-792 of 882
-
Temporal modeling of high frequency (30-100 kHz) acoustic seafloor backscatter: shallow water results
(NATO. SACLANTCEN, 1997)A temporal model of high frequency seafloor acoustic backscatter is presented and compared to recorded echoes from terrigenous sediments. Using acoustic properties correlated with mean grain size, the echo shapes and ... -
Terrain mapping with forward looking sonar on unmanned underwater vehicles
(NATO. SACLANTCEN, 1997)In the future, successful reconnaissance operations conducted in shallow water with Autonomous Underwater Vehicles will rely heavily on a high performance, high resolution, forward look sonar coupled with terrain mapping ... -
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 -
Texture analysis of sidescan sonar imagery using statistical scattering models
(NATO. SACLANTCEN, 1997)It is shown that the generalised K-distribution provides a good fir to the amplrtude statisttcs of sonar imagery from several different types of seabed sediment. A number of possible explanations for the Ricean nature of ... -
The AP-120B array processor
(NATO. SACLANTCEN, 1979/12)The Floating Point Systems array processor AP 120 B is briefly presented. An overview of the architecture is given. The most important features and the use of the AP software are described -
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 high-speed processors to propagation experiments using explosives
(NATO. SACLANTCEN, 1979/12)The possibility of analysing explosive signals directly, without an intermediate recording system, offers large improvement~ in the quality and rapid availability of results from acoustic propagation experiments. The ... -
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 ARL shipborne computer system
(NATO. SACLANTCEN, 1972/05) -
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 continuous gradient ray tracing system (CONGRATS)
(NATO. SACLANTCEN, 1971/12)CONGRATS, an acronym for the Continuous Gradient Ray Tracing System, is an integrated collection of ray tracing programs designed to model acoustic propagation and reverberation. The fundamental programs of the series, ... -
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 dynamics of information fusion: synthetic versus misassociation
(NURC, 2006/08)Fusion entails both the association and synthesis of information. If missassociations occur, they obviously undermine the gains won by synthesis, compromising the fusion product. An analytic framework is presented here to ... -
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 gravity-forced oscillations at the base of the duct on its effective depth as a channel for acoustic rays
(NATO. SACLANTCEN, 1971/12) -
The effect of suspended particulate matter on the performance of high frequency sonars in turbid coastal waters
(NATO. SACLANTCEN, 1997)Shallow coastal environments are characterised by high levels of suspended mineral particles relative lo the open ocean and such suspensions can have a significant effect on the performance of high frequency sonars operating ... -
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 ...