Far-field extrapolation of near-field acoustic measurement using inverse methods
Abstract
To perform the extrapolation of acoustic near-field measurements, two methods are presented. They are based on the inverse problem (finding a linear source distribution over a line modeling the physical system under study and computing its directivity pattern). Analytical approximations show that the problem is connected with source localization techniques, and that simple criteria can be derived on the validity of the extrapolation in a given array geometry. Numerical technique is also presented to solve the ill-conditioned linear equations appearing in these methods. Numerical simulations of point-like and extended sources show the extrapolation accuracy.
- Publication:
-
American Institute of Aeronautics and Astronautics Conference
- Pub Date:
- April 1989
- Bibcode:
- 1989aiaa.confR....E
- Keywords:
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- Acoustics;
- Extrapolation;
- Far Fields;
- Near Fields;
- Acoustic Measurement;
- Aeroacoustics;
- Directivity;
- Noise Generators;
- Acoustics