The Measurement Backscatter Coefficient from a (从一个测量后向散射系数).pdf
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IEEE TRANSACTIONS O N ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL, VOL. 44, NO. 2, MARCH 1997 515
The Measurement of Backscatter Coefficient
from a Broadband Pulse-Echo System:
A New Formulation
Xucai Chen, Dan Phillips, Karl Q. Schwarz, Jack G. Mottley, and Kevin J. Parker, Fellow, IEEE
Abstract-A new formulation for obtaining the abso- echo measurements. This formulation uses simple func-
lute backscatter coefficient from pulse-echo measurements tions with tractable approximations which are, in some
is presented. Using this formulation, performing the diffrac- instances, simple constants. In Section 11,the sonar equa-
tion correction and system calibration is straightforward.
tions for a single scatterer as well as a distribution of scat-
The diffraction correction function for the measurement of
terers are derived. The diffraction correction function is
backscatter coefficient and the acoustic coupling function
for a pulse-echo system are defined. Details of these func- defined. The effect of the attenuation is includedl by using
tions for two very useful cases are presented: a flat disk complex wave numbers and is elaborated in Appendix B.
transducer and a spherically focused transducer. Approxi- System calibration is discussed, and the acoustic coupling
mations of these functions are also provided. For a flat disk
correction coefficient is defined. In Section 111,the diffrac-
transducer, the final formulation appears as a modification
to
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