Accession Number : ADA020019

Title :   Spatial Interfrequency Correlation Effects in a Surface Scatter Channel.

Descriptive Note : Technical rept.,

Corporate Author : YALE UNIV NEW HAVEN CONN DEPT OF ENGINEERING AND APPLIED SCIENCE

Personal Author(s) : McDonald,J. F. ; Tuteur,F. B. ; Zornig,J. G.

Report Date : 18 DEC 1975

Pagination or Media Count : 48

Abstract : The effect of spatial separation on the cross-correlation between the system response functions for a two receiver surface scatter channel is investigated. The system response at the two receivers is determined for all possible pairs of frequencies. The analysis assumes relatively close separation of receivers and uses the Fresnel corrected model for surface scatter in the specular direction. The surface is assumed to be Gaussian, with typical size of boundary deformations small compared to typical Fresnel zones. The analysis shows that the correlation is approximately maximum for zero frequency separation and drops off at a rate determined by the reverberation time. For small reverberation times and small grazing angles correlation may extend over fairly large values of frequency difference. The effect of spatial separation is generally a reduction in correlation and a more rapid decreased of correlation with frequency, but this can be compensated to some extent by time shift between the two system responses. Experimental evidence is included to support the theoretical predictions presented.

Descriptors :   *Underwater sound, *Acoustic scattering, Reverberation, Fourier transformation, Signal to noise ratio, Signal processing, Approximation

Subject Categories : Acoustic Detection and Detectors
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE