| Autor: |
Cron, B. F., Schumacher, W. R. |
| Zdroj: |
Journal of the Acoustical Society of America; 1960, Vol. 32 Issue 11, p1507-1507, 1p |
| Abstrakt: |
A theoretical study of the fluctuation of the amplitude and phase associated with the return of a single frequency pulse was made. A vectorial representation was used. From this model, the conditions necessary for a first-order Rayleigh distribution of amplitudes are given, and the second-order probability distribution of the amplitudes is derived. Experimental tests were conducted in the Bermuda area. Data on volume reverberation, as well as surface return and surface plus bottom return, were obtained. The data were processed via the USL Datrac-Datatron system. Analog as well as digital processing was used. An analog electronic circuit was used to generate the Hilbert transform of the returned signal. The return signal and the Hilbert transform were both sampled by the 'Datrac' system at a rate of the reciprocal of the bandwidth. The analog values thus obtained were then converted to digital form by the 'Datrac' system. From the digital values of the original time function and the Hilbert transform of the time function, the Datatron 205 was programmed to compute the corresponding values of the envelope and the phase of the carrier frequency. Experimental histograms were obtained by the computer for these values. The experimental histograms were compared with the expected theoretical distributions. Statistical tests of goodness of fit were conducted on these data. The results showed the theoretical assumptions to be valid. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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