Investigation of Finite Amplitude Attenuation
Final technical rept. 29 Mar-31 Dec 1975
AMETEK EL CAJON CA STRAZA DIV
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This is the final technical report on a study of finite amplitude attenuation. The program objective has been to determine by experimental and theoretical means the limitations imposed by finite amplitude attenuation on the performance of parametric sonars. The results are intended for use in assessing the potential of parametric receivers and transmitters in military applications. The axial response of the parametric receiving array has been calculated in two ways. The first is by use of a one dimensional model in which the secondary signal levels are predicted from weak shock theory. The second is by numerical evaluation of the scattering integral solution in which finite amplitude attenuation is introduced by means of a taper function derived from the one dimensional solution. An experiment has been performed in which the axial secondary signal level as a function of pump source level was measured. These data agree with the theoretical results, but the agreement is not conclusive because the maximum pump source level was not sufficiently high. However, a comparison with data from another investigation confirms the theory for cases when the receiving hydrophone is well in the farfield of the pump.
- Acoustic Detection and Detectors