Reprints: Recent submissions
Now showing items 481-500 of 548
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Seismic and hydroacoustic sensing of infrasonic noise in coastal waters
(NATO. SACLANTCEN, 1982/06)Three-component ocean-bottom seismometers with radio links have been deployed in coastal waters to investigate natural and man-made noise at extremely low frequencies. Seismograms from one or up to three sensor stations ... -
Low-frequency seismic and hydroacustic noise measurements in a fjord
(NATO. SACLANTCEN, 1982/06)Low frequency ambient noise signals from an ocean bottom seismometer (oBS) put on the sea floor of a Norwegian fjord have been studied. The instrument contains 3 seismometers and one hydrophone, and signals from all 4 ... -
Arctic ambient noise statistical measurement results and their implications to sonar performance improvements
(NATO. SACLANTCEN, 1982/06)Recent analyses of FRAM II arctic data have shown that under ice ambient noise can be at times highly impulsive and non-Gaussian. The analyses included time domain statistical measurements which were consistent with ... -
Le programme Ulysse: réseau de bouées pour l'étude statistique du bruit ambiant sous-marin
(NATO. SACLANTCEN, 1982/06) -
Flow noise interference in measurements of infrasonic ambient noise
(NATO. SACLANTCEN, 1982/06)Estimates are presented of the local noise generated at infrasonic frequencies by turbulent water flowing in the vicinity of hydrophones used for measurements of ambient noise in the sea. Three situations are discussed: a ... -
Role of propagation in ambient noise
(NATO. SACLANTCEN, 1982/06)To be useful for modern ASW systems design and analyses, descriptions of ambient noise fields must go beyond average omnidirectional spectra and include horizontal and vertical patterns, fluctuations with time, dependencies ... -
Acoustic source characteristics of merchant ships
(NATO. SACLANTCEN, 1982/06)Merchant ships are sources of broadband acoustic noise which can interfere with and confuse ocean surveillance. The purpose of this discussion is to review: the status of research on and measurements of merchant ship ... -
Geometrical properties of underwater sound propagation
(NATO. SACLANTCEN, 1971/12) -
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 ... -
Some high efficiency digital signal processing techniques for high speed signal processing systems
(NATO. SACLANTCEN, 1979/12)Some high efficiency digital signal processing techniques, based on digital filtering are presented for real-time general-purpose, high-speed signal processing systems. At first high efficiency one-dimensional and ... -
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 ... -
Sonar beam-forming with an array processor in real time
(NATO. SACLANTCEN, 1979/12)A real-time sonar beam-forming system is described which consists of a minicomputer as host computer and an array processor. Beam-forming is accomplished by using the FFT algorithm in the processor. The system is also ... -
High-speed simulation of an underwater acoustic field using an array processor
(NATO. SACLANTCEN, 1979/12)A computer model PAREQ for simulating the acoustic field of sound propagating in a complicated ocean environment has been installed on a realtime computer system (HP MX21) which includes an array processor (MAP 300). The ... -
Laboratory utilization of a standard signal processor
(NATO. SACLANTCEN, 1979/12)The AN/UYS-l Advanced Signal Processor (ASP), or PROTEUS, is the U.S. Navy's standard signal processor and is being utilized in several systems. For shipboard use, the ASP is used as a processor with no peripherals, generally ... -
Real-time expanded-band beamforming using a complex heterodyner and fast array processor
(NATO. SACLANTCEN, 1979/12)At the Defense Research Establishment Atlantic Dartmouth, Nova Scotia, Canada a data aquisition sytem been engineered to monitor and beamform data from element line arrays. This system has been designed to with either towed ... -
MASCOT - a modular software construction system
(NATO. SACLANTCEN, 1979/12) -
Comparison of ray tracing predictions with wideband propagation measurements
(NATO. SACLANTCEN, 1971/12)The paper gives an illustration of the latest methods which have been developed at SACLANTCEN for the experimental study of sound propagation in deep water. They are based on a high sampling of the sound field produced by ... -
Signal-processing language and operating system
(NATO. SACLANTCEN, 1979/12)Signal Processing Language/One (SPL/I) was developed at the Naval Research Laboratory (NRL) as a high-level computer programming language for signal processing. SPL/I is the first high-level language to be designed for ... -
A modular signal processing software development system
(NATO. SACLANTCEN, 1979/12)A software development system is being built by the U.S. Naval Research Laboratory (NRL) to aid production of modular signal processing software for U. S. Navy airborne ASW platforms using the Navy's Advanced Signal Processor ... -
System functional migration: high-level language to hardware
(NATO. SACLANTCEN, 1979/12)This paper intends to examine system functional allocation among available processing resources in a systematic way. The discussion will focus first on the criteria for assigning functions to processors, that is, horizontal ...