Browsing Technical Reports by Title
Now showing items 22-41 of 322
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A simple deconvolution method for NAPOLI'85
(NATO. SACLANTCEN, 1991/10)An inverse filter (deconvolution in the frequency domain) is applied -
A study of the uncertainty in estimate seabed properties as a result of goeacoustic inversion algorithms
(NATO. SACLANTCEN, 2003/10)This paper investigates the inherent uncertainty in estimated seabed properties derived from matched-field geoacoustic inversion algorithms. This algorithm-induced uncertainty must be considered when interpreting inversion ... -
A theoretical and experimental study of the kinematics of a coring tube accelerated in water by hydrostatic pressure
(NATO. SACLANTCEN, 1964/03)The implosion at great marine depths of a system composed of a light tube, which is closed at one end by a light cap and at the other by a heavy piston, is examined theoretically and experimentally. Special attention has ... -
A towed CTD chain for two-dimensional high resolution hydrography
(NATO. SACLANTCEN, 1997/04)The need for accurate two-dimensional datasets of temperature and salinity in the upper ocean led to the development of a new type of towed chain. Low-cost sensors are moulded in fins and may be randomly placed on the tow ... -
Accuracy of synthetic aperture sonar micronavigation using a displaced phase centre antenna
(NATO. SACLANTCEN, 1999/02)This work evaluates the accuracy of multi-element synthetic aperture sonar (SAS) micronavigation based on the concept of displaced phase centre antenna (DPCA). The Cramér-Rao lower bound (CRLB) for the joint estimation of ... -
Acoustic bottom characterization of a shallow water area west of Mallorca
(NATO. SACLANTCEN, 1995/12)An experiment was conducted in shallow water on the Balearic Shelf -
Acoustic bottom reflectivity
(NATO. SACLANTCEN, 1989/06)Acoustic reflectivity from the seafloor is often an important factor influencing the performance of ASW systems in different environments, such as in deep water when the bottom bounce paths are used, and in general in ... -
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 ...