Browsing Reprints by Issue Date
Now showing items 1-20 of 548
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Magnetic, gravity and depth surveys in the Mediterranean and Red Sea
(NATO. SACLANTCEN, 1965/04)This report is a copy of a paper published in Nature, Vol. 204, 4965, 1964: 1245-1248 by T.D. Allan of this Centre, H. Charnock of this Centre at the time of the surveys but now of the National Institute of Oceanography, ... -
A theoretical method for the prediction of underwater explosion pulses at caustics
(NATO. SACLANTCEN, 1971/12)Our concern [Refs. 1 and 2J is with the effect of refraction on the long range propagation of underwater explosion shock waves. Here, as with acoustic sources, ray tracing can be used to predict refraction effects. From ... -
The continuous gradient ray tracing system (CONGRATS)
(NATO. SACLANTCEN, 1971/12)CONGRATS, an acronym for the Continuous Gradient Ray Tracing System, is an integrated collection of ray tracing programs designed to model acoustic propagation and reverberation. The fundamental programs of the series, ... -
Theoretical calculation of transmission loss in the ocean
(NATO. SACLANTCEN, 1971/12)The topic that is dealt with in this paper is a method for c omputation of acoustic transmission loss by sound propagation in the ocean. The method i s based on the ray theory which is used in connection with an acoustic ... -
Methods used in France for the calculation of sound fields
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Considerations relating to the calculation of sound velocity
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Considerations on numerical and experimental propagation models for two-dimensional variations of medium properties
(NATO. SACLANTCEN, 1971/12)One of the problems the FWG is dealing with is the prediction of sound propagation loss in shallow water. A part of this problem is being treated by bringing measurements and numerical computation into relationship. -
The effect of gravity-forced oscillations at the base of the duct on its effective depth as a channel for acoustic rays
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Some comments on ray theory with examples from current NUC ray trace models
(NATO. SACLANTCEN, 1971/12)Three topics were covered in this paper: 1. Ray Sweep-out Method - a technique for calculating sound intensities at a large number of receiver points in range and depth . 2. Bi-static Reverberation Model - a technique based ... -
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 ... -
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 ... -
Application of the Riesz potential to the Cauchy problem for wave propagation in an inhomogeneous medium
(NATO. SACLANTCEN, 1971/12)The method of Riesz [Ref. l] for the solution of hyperbolic partial differential equations is applied to the Cauchy problem for the wave equation. It is shown that the first term in the Riesz potential function, which is ... -
Special formulation of modified ray analysis for machine computation
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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 ... -
Approximate methods for ray tracing
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Position and shape of the surface shadow zone
(NATO. SACLANTCEN, 1971/12)From surface reverberation studies conducted by SACLANTCEN's Target Classification Group"C , it has been found necessary to know before any sea experiment the precise position of the first surface shadow zone. Since normal ... -
Sensitivity of ray theory to input data
(NATO. SACLANTCEN, 1971/12)Acoustic propagation problems which are solved using ray theory require certain input data. In particular, the source and receiver locations, sound-velocity field and bottom and surface conditions are required. Frequently, ... -
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 ... -
Ray tracing on a mini-computer
(NATO. SACLANTCEN, 1971/12)It would appear that most people engaged in solving problems in ray- tracing, use programs written for large computers . These machines commonly have large memory sizes, fast cycle times and large word length 0 This paper ...