Acoustic Scattering for Buried Objects at High Frequencies - A Ray Theoretic Approach

1997 ◽  
Author(s):  
Subramnaiam D. Rajan
Keyword(s):  
Acoustic Scattering ◽  
Theoretic Approach ◽  
High Frequencies ◽  
Buried Objects

scholarly journals Bearing and Range Estimation Algorithm for Buried Object in Underwater Acoustics

2009 ◽  
Vol 2009 ◽  
pp. 1-4
Author(s):  
Dong Han ◽  
Caroline Fossati ◽  
Salah Bourennane ◽  
Zineb Saidi
Keyword(s):  
Underwater Acoustics ◽  
Classical Model ◽  
Acoustic Scattering ◽  
Estimation Algorithm ◽  
Signal Classification ◽  
Music Algorithm ◽  
Range Estimation ◽  
Multiple Signal Classification ◽  
Buried Objects ◽  
Buried Object

A new algorithm which associates (Multiple Signal Classification) MUSIC with acoustic scattering model for bearing and range estimation is proposed. This algorithm takes into account the reflection and the refraction of wave in the interface of water-sediment in underwater acoustics. A new directional vector, which contains the Direction-Of-Arrival (DOA) of objects and objects-sensors distances, is used in MUSIC algorithm instead of classical model. The influence of the depth of buried objects is discussed. Finally, the numerical results are given in the case of buried cylindrical shells.

Acoustic scattering by buried objects in a rigid porous material

2001 ◽  
Author(s):  
Doru Velea ◽  
Craig J. Hickey ◽  
James M. Sabatier
Keyword(s):  
Porous Material ◽  
Acoustic Scattering ◽  
Buried Objects

The design of a boundary element package for treating acoustic scattering from buried objects

2006 ◽  
Vol 120 (5) ◽  
pp. 3143-3143
Author(s):  
Ralf Burgschweiger ◽  
Martin Ochmann ◽  
Bodo Nolte
Keyword(s):  
Boundary Element ◽  
Acoustic Scattering ◽  
Buried Objects

Quasi-Periodic Oscillations in Dwarf Novae

1979 ◽  
Vol 46 ◽  
pp. 77-88
Author(s):  
Edward L. Robinson
Keyword(s):  
Binary Systems ◽  
Outer Edge ◽  
Light Curves ◽  
Close Binary ◽  
Bright Spot ◽  
Dwarf Novae ◽  
Periodic Oscillations ◽  
High Frequencies ◽  
Short Period ◽  
Typical Time

Three distinct kinds of rapid variations have been detected in the light curves of dwarf novae: rapid flickering, short period coherent oscillations, and quasi-periodic oscillations. The rapid flickering is seen in the light curves of most, if not all, dwarf novae, and is especially apparent during minimum light between eruptions. The flickering has a typical time scale of a few minutes or less and a typical amplitude of about .1 mag. The flickering is completely random and unpredictable; the power spectrum of flickering shows only a slow decrease from low to high frequencies. The observations of U Gem by Warner and Nather (1971) showed conclusively that most of the flickering is produced by variations in the luminosity of the bright spot near the outer edge of the accretion disk around the white dwarf in these close binary systems.

Determination of developmental stage to obtain high frequencies of embryogenic microspores in Brassica napus

1992 ◽  
Vol 84 (3) ◽  
pp. 417-424 ◽  
Author(s):  
Cheryl A. Telmer ◽  
Daina H. Simmonds ◽  
William Newcomb
Keyword(s):  
Brassica Napus ◽  
Developmental Stage ◽  
High Frequencies
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