Browsing Reprints by Subject "Ray tracing"
Now showing items 1-20 of 29
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A general purpose software system for applications in different fields of physics
(NATO. SACLANTCEN, 1979/12)The paper presents the principle of a software system (FTSS) developed by the Danish Defence Research Establishment (DDRE) for applications in different fields of physics. Software is made up by independent modules exchanging ... -
A review of some developments in ray tracing at the Naval Air Development Center
(NATO. SACLANTCEN, 1971/12)The Naval Air Development Center has a comprehensive ray-tracing program which has been extensively used for a number of years not only by our own laboratory, but also by other naval activities and private contractors . ... -
Adaptive normalization of active sonar data
(NURC, 2006/08)In active sonar detection the background interference is reduced through normalization prior to applying a detection threshold. From the two mainstream normalization algorithms, i.e. the sliding window and the split window, ... -
An experimental verification of a geometric acoustic approximation
(NATO. SACLANTCEN, 1971/12)This paper sets out to show that a very simple ray treatment may be used to give a surprisingly good estimate of a sound field, even in conditions where the criteria for the use of geometric acoustics are apparently not fulfilled. -
Application of ray tracing with horizontal gradient to monostatic boundary reverberation
(NATO. SACLANTCEN, 1971/12)Presented is the current work being done at the Naval Research Laboratory (NRL) on the development of a series of computer programs to predict long range, low frequency, monostatic boundary reverberation. The emphasis is ... -
Approximate methods for ray tracing
(NATO. SACLANTCEN, 1971/12) -
Calculation of propagation losses in a medium with a velocity profile approximated by a number of Epstein profiles
(NATO. SACLANTCEN, 1971/12)This paper presents a digital ray-theory program, by which the ray trace, travel time and intensity can be calculated for velocity profiles approximated by a number of Epstein functions. -
Calculation of reverberation and average intensity of broadband acoustic signals in the ocean by means of the RAIBAC computer model
(NATO. SACLANTCEN, 1976/04)Based on the conventional ray-tracing principle, a fast numerical algorithm is developed that calculates averaged propagation loss and reverberation of underwater sound. The averaging is performed by summing incoherently ... -
Comments on the ray theory approximation
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Comparison of CONGRATS ray tracing predictions with MEDUSA measurements of reverberation
(NATO. SACLANTCEN, 1971/12)From the user's point of view, ray tracing is just a computer procedure which is inserted into larger programs of different degrees of complexity . The following table indicates in which kind of programs this procedure is ... -
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 ... -
Geometrical properties of underwater sound propagation
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Intensity at caustics
(NATO. SACLANTCEN, 1971/12)The classical divergence expressions predict an infinite intensity at caustics. This infinite intensity is a fundamental limitation of geometrical acoustics (ray theory). The intensity at a caustic is of primary concern ... -
Intensity calculations along a single ray
(NATO. SACLANTCEN, 1971/12)A method is presented for the calculation of sound intensity using only one ray. The sound velocity profile is assumed to be continuous up to the second derivative and it is supposed that the ray equations are solved ... -
Methods used in France for the calculation of sound fields
(NATO. SACLANTCEN, 1971/12) -
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 ... -
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 ... -
Ray tracing on a mini-computer
(NATO. SACLANTCEN, 1972/05)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 si~es, fast cycle times and large word length . This paper ... -
Rays and statistical diffraction theory
(NATO. SACLANTCEN, 1971/12)A method of extending ray tracing is proposed, such that mediumscale irregularities of a statistical nature are taken into account along with large-scale irregularities in refractive index of the medium.