Browsing Technical Reports by Title
Now showing items 30-49 of 322
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Acoustic impact of upper ocean models
(NATO. SACLANTCEN, 1989/12)The upper mixed-surface layer of the ocean, with its homogeneous vertical temperature profile, provides a somewhat special acoustic propagation environment where the sound speed will increase (due to pressure) down to the ... -
Acoustic models at SACLANTCEN
(NATO. SACLANTCEN, 1995/03)The Environmental Modelling Group at SACLANTCEN maintains a suite of computer codes to model sound propagation in the ocean. This suite contains numerical models to cover all environmental conditions and acoustic frequencies ... -
Acoustic source-level measurements for a variety of merchant ships
(NATO. SACLANTCEN, 1988/07)This report describes a set of 50 source spectra obtained from merchant ships of opportunity near Genova, Italy. These spectra were obtained from radiated-noise spectra measured on a towed array and a transmission-loss ... -
Active signal detection in shallow water using the Page test
(NATO. SACLANTCEN, 1996/11)The use of active sonar in shallow water results in received echoes that may be considerably spread in time compared to the transmitted wave form. The duration and structure of the spreading and the time of occurrence of ... -
Airborne transmission risk: ventilation and filtration in occupied buildings during the SARS-CoV-2 pandemic
(CMRE, 2021-03)During the SARS-CoV-2 pandemic, many mitigation strategies have been employed to reduce the risk of transmission between individuals, including hygienic practices such as washing hands and objects frequently, wearing face ... -
Alternative approach to passive sonar
(NATO. SACLANTCEN, 1987/10)An alternative approach to spatial processing for passive sonar is proposed and discussed. It is -
An acoustic system for releasing submerged oceanographic buoys from their anchors on demand using a 1.4 kc compact source
(NATO. SACLANTCEN, 1963/12)The paper describes an anchor-releasing device for the recovery of moored oceanographic equipment. The releaser is actuated by a remote acoustic signal emitted by a small and powerful 1400 cps sound source rather than by ... -
An acoustic, high resolution, sediment profiler
(NATO. SACLANTCEN, 1966/11)An acoustic sediment profiler is described that utilizes short 50 kHz pulses to achieve a high range resolution. In trials in shallow water, penetration depths of about 9 m and resolution of about 25 cm were obtained. ... -
An analogue recording system for recording pulse series
(NATO. SACLANTCEN, 1964/04)An analogue recording system for the visual display of pulse series intermittently received from oceanographic sensors is described. It is composed of a mechanically-modified pen recorder and a newly designed electronic ... -
An analysis of selected satellite data of the Aegean area with the STARS software
(NATO. SACLANTCEN, 1986/11)Data from selected orbits of the NOAA-7 meteorological satellite are used for an exploratory analysis -
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 approach to robust map generation from multibeam bathymetric data
(NATO. SACLANTCEN, 1997/10)During the last twenty years, many multibeam bathymetric sonars have been produced. The instrumentation is usually accompanied by a system able to produce a seafloor map from the sonar data. There are also several public ... -
An automated instrument for testing and monitoring oceanographic mooring cables and ropes
(NATO. SACLANTCEN, 1997/09)Underwater acoustic experiments at the NATO SACLANT Undersea Research Centre, La Spezia, Italy (SACLANTCEN) are largely dependent on moored and towed instrumentation. Every year up to 500 cable terminations am made and ... -
An automatic approach to ship detection in spaceborne synthetic aperture radar imagery: an assessment of ship detection capability using RADARSAT
(NATO. SACLANTCEN, 2000/12)This report describes a methodology for automated ship and wake detection in space-based synthetic aperture radar (SAR) imagery. The methodology incorporates a multistage approach involving several algorithms which can ... -
An autonomous undersea surveillance vehicle: concept and operational feasibility
(NATO. SACLANTCEN, 1988/12)The concept of autonomous undersea vehicles (AUVs) is becoming feasible through the increasing practicality of artificial intelligence, decreasing size and cost of computers, and improved technical capabilities. This paper ... -
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 improvement in the design of the towed nuclear spin magnetometer
(NATO. SACLANTCEN, 1963/06) -
An instrument for measuring evaporation
(NATO. SACLANTCEN, 1965/09)An evaporation rate meter, or evaporimeter, has been devised that shows promise of directly measuring the rate of evaporation near the sea surface. The simplicity of the instrument indicates that it may be of interest to ... -
An unrestricted linear random walk with negative exponentially distributed step lengths
(NATO. SACLANTCEN, 1966/06)An account is given of the theory of a doubly infinite linear random walk in which step lengths have a negative exponential distribution and the direction of each step is not necessarily equiprobable. The problem of first ... -
Analysis of a signal starting time estimator based on the Page test statistic
(NATO. SACLANTCEN, 1995/12)The time of the most recent reset to zero of the Page test statistic is proposed as an estimator of the starting time of a signal. The probability mass function of the estimator is determined analytically subject to a ...