Browsing CMRE Publications by Subject "Underwater acoustics"
Now showing items 41-60 of 73
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Parameter estimation using multi-frequency range-dependent acoustic data in shallow water
(NATO. SACLANTCEN, 1996/11)The estimation of all forward model parameters - geometric, geoacoustic, -
Principles and methods of core analysis at the SACLANT ASW Research Centre
(NATO. SACLANTCEN, 1967/08)The methods and accuracy of measuring core parameters at the SACLANTCEN are described. Those for measuring sound velocity and electrical resistivity are explained in detail. -
Processing of broadband acoustic signals
(NATO. SACLANTCEN, 1972/05) -
Ray convergence in a flux-like propagation formulation
(CMRE, 2014/01)The energy flux formulation of waveguide propagation is closely related to the incoherent mode sum, and its simplicity has led to development of efficient computational algorithms for reverberation and target echo strength, ... -
Review of numerical models in underwater acoustics including recently developed fast-field program
(NATO. SACLANTCEN, 1984/12)Two papers given by SACLANTCEN personnel at the NATO Advanced Research Workshop on Hybrid Formulation of Wave Propagation and Scattering at Castel Gandolfo, Rome, Italy on 30 August to 3 September 1983 are published as a ... -
Riverine environmental acoustics at an ocean estuary
(NATO. SACLANTCEN, 1997)The purpose of these studies was to investigate some of the more important geoacoustrc parameters that might govern the use of high frequency sonar in muddy rivers, where they flow into the sea. Both environmental and ... -
SAFARI Seismo-Acoustic Fast field Algorithm for Range-Independent environments: user's guide
(NATO. SACLANTCEN, 1988/09)An efficient algorithm has been developed for solving the depth-separated wave equation in general fluid/solid horizontlly stratified media. The algorithm has been built into a general-purpose package of computer codes ... -
Scintillation instrument for remote environmental analysis (SIREN)
(NATO. SACLANTCEN, 1999/02)A high frequency acoustic propagation instrument which was developed to study ocean variability in the Strait of Istanbul (Bosporus) is described. The scintillation instrument for remote environmental analysis (SIREN) was ... -
Secure underwater acoustic networks: current and future research directions
(CMRE, 2019/06)Underwater Acoustic Networks (UANs) are widely used in various applications such as climate change monitoring, pollution control and tracking, tactical surveillance and offshore exploration. However, limited consideration ... -
Separation of measured noise coherence matrix into Toeplitz and Hankel parts
(CMRE, 2017/08)The cross-spectral density of ocean ambient noise is usually estimated from the product of the complex hydrophone signals, each of which already corresponds to the summed responses of sources from all angles. The true ... -
Simultaneous analysis in real time
(NATO. SACLANTCEN, 1972/05) -
Sound attenuation between 200 and 10,000 cps measured along single paths
(NATO. SACLANTCEN, 1965/09)In the deep Mediterranean basins, the water is perfectly isothermal below 400 m, and the deep refracted ray gives clear signals up to 40 km, with a spreading loss free from any frequency-dependent effect. Exploiting this ... -
Status of ray theory development of Naval Undersea Research and Development Center
(NATO. SACLANTCEN, 1971/12)The first part of this paper discusses NUC (Naval Undersea Research and Development Center) work on the accuracy and validity of ray theory. By comparing the range to convergence zones as indicated by experiment and by ... -
Subcritical penetration of narrow Gaussian beams into sediments
(NATO. SACLANTCEN, 1988/03)Complete wave-theory solutions have been obtained numerically for both the reflected and the transmitted fields associated with a narrow Gaussian beam incident on a water-sediment interface near the critical grazing angle. ...