Acoustic Reflection from Surfaces and Shapes
Author: Werner G. Neubauer
Publisher:
Published: 1986
Total Pages: 416
ISBN-13:
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Author: Werner G. Neubauer
Publisher:
Published: 1986
Total Pages: 416
ISBN-13:
DOWNLOAD EBOOKAuthor: Laurence Floyd Wagner
Publisher:
Published: 1974
Total Pages: 158
ISBN-13:
DOWNLOAD EBOOKAuthor: Raymond H. Ferris
Publisher:
Published: 1970
Total Pages: 18
ISBN-13:
DOWNLOAD EBOOKAn experiment on underwater acoustic relfection from the ocean's surface was conducted in a water depth of 32 m by utilizing an omnidirectional, 3.5-kHz fixed source at a submerged depth of 16 m. Two-cycle pulses at a repetition rate of 10 pulses per second were received on a hydrophone suspended at a depth of 10.7 m from a small boat. Underwater grazing angles ranged from 15 to 40 degrees. Surface reflection loss was observed to vary over a range of approximately 20 dB with periods closely associated with the predominant water wave periods. Surface reflection gains of up to 5 dB occurred frequently. The average loss ranged from 1 dB at a grazing angle of 15 degrees to 4 dB at an angle of 40 degrees, with only a slight dependence on direction of propagation relative to the direction of the sea. Signals propagated via the surface-reflected path, when correlated with signals propagated via the direct path, exhibited an average peak value of normalized cross correlation of 0.95. (Author).
Author:
Publisher:
Published: 1991
Total Pages: 19
ISBN-13:
DOWNLOAD EBOOKA possible technique for studying the acoustic reflection from continuous plane surfaces such as flat plates covered with thin anechoic coatings is discussed. It is particularly directed to complex coatings which include a regular array of non-homogeneous inclusions within their structures. The method involves the experimental determination of a position-dependent quantity which can be viewed as either a surface transfer admittance or a surface transfer mobility function. This function can then be used in a mathematical convolution procedure to determine the nature of the reflected wave from the surface when it is ensonified by an incident uniform plane wave arriving in a direction normal to the plate surface. The basic theory behind the proposed method is presented for a surface having a periodic, two-dimensional spatial variation. As a side issue, this approach raises a question as to the applicability of an 'average surface admittance' approach used previously to estimate reflection coefficients of Alberich coatings. The basic elements of an experimental system for measuring the surface admittance functions are discussed.
Author: Pier Paolo Delsanto
Publisher: Taylor & Francis US
Published: 1998
Total Pages: 456
ISBN-13: 9789056995492
DOWNLOAD EBOOKAuthor: Fred Tudor Erskine
Publisher:
Published: 2013
Total Pages: 188
ISBN-13:
DOWNLOAD EBOOKAuthor: julian r. frederick william c. meecham irene v.schenated james e. lesch
Publisher:
Published: 1956
Total Pages: 103
ISBN-13:
DOWNLOAD EBOOKAuthor: Brandon M. Heller
Publisher:
Published: 2017
Total Pages: 118
ISBN-13:
DOWNLOAD EBOOKAuthor: C. I. Sach
Publisher:
Published: 1991
Total Pages: 18
ISBN-13: 9780646054179
DOWNLOAD EBOOKAuthor: 姚奕廷
Publisher:
Published: 2017
Total Pages:
ISBN-13:
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