Browsing CMRE Publications by Title
Now showing items 73-92 of 882
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A wave-theoretic method for estimating the effects of internal tides on acoustic wave transmission
(NATO. SACLANTCEN, 1975/10)The effect of the first mode semidiurnal internal tide on a ducttype sound speed profile was approximated by varying the minimum velocity of the parabolic profile in a sinusoidal fashion with a period of 12.42 hours. The ... -
About the effective Doppler sensitivity of certain nonlinear chirp signals (NLFM)
(NATO. SACLANTCEN, 1993/08) -
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 ... -
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 ... -
Acoustic ambient noise in the Barents Sea
(NATO. SACLANTCEN, 1982/06)Recorded observations of acoustic ambient noise in the Western Barents Sea are presented. The observations were made in a position approximately 100 km North of North Cape in Norway, with the hydrophone on the bottom - ... -
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 characterization of a shallow water site
(NATO. SACLANTCEN, 1993/08)Results are presented from an exercise aimed at providing a low frequency active sonar environmental characterization of a specific shallow water site in the Gulf of Mexico. Downward refracting acoustic transmission and ... -
Acoustic characterization of submerged aquatic vegetation
(NATO. SACLANTCEN, 1997)The acoustic characteristics of submerged aquatic vegetation (SAV) were investigated in order to enhance the performance of mine-hunting and weapon sonars in littoral reglons. The specres of seagrass initially studied was ... -
Acoustic effects of internal microstructure
(NATO. SACLANTCEN, 1975/10) -
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 noise models
(NATO. SACLANTCEN, 1975/10)The question of modeling the vertical directionality of ambient noise in the ocean is considered. The problem of converting from a description in terms of directional density function to a description in terms of the ... -
Acoustic propagation models as viewed by the sonar systems designer
(NATO. SACLANTCEN, 1971/12)The purpose of this paper is to consider the efforts performed in the development of ray acoustic propagation analyses from the viewpoint of advanced sonar system design. In particular, those parameters required of such ... -
Acoustic propagation through oceanic fronts
(NATO. SACLANTCEN, 1971/12)A resume was given of recent experiments in the Mediterranean, East of Malta, designed as a preliminary test of the effect of oceanic fronts on acoustic propagation. It was apparent that in certain circumstances the ... -
Acoustic properties of the sea floor: a review
(NATO. SACLANTCEN, 1975/10) -
Acoustic scattering from rough surfaces
(NATO. SACLANTCEN, 1975/10)A review of scattering from the ocean bottom and ocean ice cover is given. Areas of deficiency are cited. -
Acoustic scintillations of acoustic waves
(NATO. SACLANTCEN, 1975/10) -
Acoustic signal dispersion and distortion by shallow undersea transmission channels
(NATO. SACLANTCEN, 1997)The undersea littoral is an adverse medium for acoustic signal transmission to horizontal ranges of many water depths. Reflections and scattering in the bounded, nonhomogeneous channel disperse the arrivaj of received ...