Browsing CMRE Publications by Subject "Sonar arrays"
Now showing items 1-20 of 36
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A real time system for towed array calibration and performance analysis, or how to get 50 dB sidelobes from a towed array
(NATO. SACLANTCEN, 1982/06)Sidelobe suppression levels of 30 dB for a towed array are generally considered excellent; values above that are considered exceptional or unachievable. However, 40 t o 50 dB suppression levels have been achieved and ... -
A versatile signal-processing system for producing the angular and frequency distribution of acoustic energy in real time
(NATO. SACLANTCEN, 1979/12)For a number of years the US Naval Research Laboratory (NRL) has been conducting a research program in underwater sound propagation using large aperture hydrophone arrays. This research requires the spectral and angular ... -
Achievable signal gains for line arrays in shallow water
(NATO. SACLANTCEN, 1993/08)The well-documented conformance of signal gain to a 20 log n relationship for deep water, refracted paths, does not apply to shallow water where angular spreading effects from boundary roughness limit the signal gains that ... -
Advanced digital processor research at DREA
(NATO. SACLANTCEN, 1979/12)This informal presentation deals with an array processor built by ESE Ltd of Toronto under contract to the Defense Research Establishment Atlantic, Dartmouth, Nova Scotia, Canada. The processor and software was delivered ... -
An analytical study of source localization in shallow water by matched-field processing of horizontal arrays
(NATO. SACLANTCEN, 1992/08)Over the last few years a large number of studies have reported results of range-depth localization of sound sources by matched-field processing of vertical arrays in known environments. The performance of matched-field ... -
An experimental study in forming a long synthetic aperture in the sea
(NATO. SACLANTCEN, 1992/09)Successful experimental testing of synthetic aperture techniques for sonar systems have been very limited and only few results, including very stable CW signals, have been published. These experimental results and theoretical ... -
An introduction to adaptive array processing
(NATO. SACLANTCEN, 1979/12)Array processing systems which can respond to an unknown interference environment are currently of considerable interest. The fundamentals of such systems are by no means new - basically they depend on Weiner's filter ... -
Array and cable tracking data through ship maneuvers
(NATO. SACLANTCEN, 1993/08)This paper presents tracking results from two sea tests in which a towed cable and array were tracked at the Atlantic Undersea Test and Evaluation Center (AUTEC). The tracking tests involved instrumenting the cable with ... -
Array shape determination with a real-time model
(NATO. SACLANTCEN, 1993/08)A shape estimation scheme based on precomputed frequency-domain solutions of array motion is presented. The boundary conditions supporting each solution are discrete Fourier transform (OFT) components of sensor measurements, ... -
Arrays and array processors: future real time applications in oceanography and sonar
(NATO. SACLANTCEN, 1979/12)In the last several years oceanographic applications of arrays have increased substantially. The spatial resolution and redundancy provided by arrays have been necessary in the interpretation of signal propagation in complex ... -
AUV active perception: exploiting the water column
(CMRE, 2019/06)Autonomous Underwater Vehicles (AUVs) present a low-cost alternative or supplement to existing underwater surveillance networks. The NATO STO Centre for Maritime Research and Experimentation is developing collaborative ... -
Deployable underwater surveillance systems: analysis of experimental results: part III
(NATO. SACLANTCEN, 1999/04)Deployable Underwater Surveillance Systems (DUSS) are a new active sonar concept based on a distributed network of small multistatic transmitter / receiver nodes. This study analyzes data acquired during the period 29 June ... -
Depth dependence of directionality of ambient noise in the North Pacific: experimental data and equipment design
(NATO. SACLANTCEN, 1982/06)Ambient ocean noise studies have been part of the research program of the Marine Physical Lab (MPL) for many years. In recent years this work has included several studies of the depth dependence of vertical directionality ... -
DUSS97: source localization and environmental inversion using vertical array data
(NATO. SACLANTCEN, 1998/08)Results on source localization and environmental inversion using experimental data acquired on a vertical line array are presented. Global inversion methods based on genetic algorithms are utilized to estimated the range ... -
GLider Acoustics Sensing of Sediments (GLASS): experiments and data analysis
(CMRE, 2013/12)Seabed characteristics (geoacoustic properties and scattering strength) are critical parameters for sonar performance predictions. However, this bottom information is considered very difficult and expensive to achieve in ... -
Glider-based seabed characterization using natural-made ambient noise
(CMRE, 2019/06)Seabed characteristics (geoacoustic properties and scattering strength) are critical parameters for sonar performance predictions. However, this bottom information is considered very difficult and expensive to achieve in ... -
Glider-based seabed characterization using natural-made ambient noise
(CMRE, 2019/06)Seabed characteristics (geoacoustic properties and scattering strength) are critical parameters for sonar performance predictions. However, this bottom information is considered very difficult and expensive to achieve in ... -
Horizontal array gain in shallow water
(NATO. SACLANTCEN, 1980/12)Some results of a comprehensive model study on the use of horizontal hydrophone arrays in shallow water are presented. Well-known signal processing techniques are applied to a shallow-water sound propagation model in order ... -
Localization of small surface vessels through acoustic data fusion of two tetrahedral arrays of hydrophones
(CMRE, 2014/01)Detection and tracking of vessels is important in confined areas such as marine parks or harbors. Nowadays, the presence of ships can be accurately monitored either by radar or via AIS system, while small vessels, which ... -
Long range, large throughput radio data links for DUSS (Deployable Underwater Surveillance Systems)
(NATO. SACLANTCEN, 1999/10)Two mono-directional radio telemetry systems are described operating from a buoy to NRV Alliance at frequencies of 0.4 and 2.28 GHz. Digital data at 2 Mbps were transmitted close to the sea surface, collecting information ...