Accession Number : AD0648010

Title :   CROSS-CORRELATION LOSS CAUSED BY BOTTOM REFLECTION,

Corporate Author : NAVY UNDERWATER SOUND LAB NEW LONDON CONN

Personal Author(s) : Cron,Benjamin J. ; Shaffer,Robert L.

Report Date : 27 DEC 1966

Pagination or Media Count : 24

Abstract : The cross-correlation between an incident (direct) and a bottom-reflected pulse is analyzed, and the physical models of the reflection process are briefly reviewed. A three-layer model is assumed for the analysis performed in this report. The bottom is considered to act as a linear filter, and the transfer function, which includes the general case of attenuation and phase shift, is given for the filter. A random function with a flat spectrum and finite bandwidth is transmitted, and the cross-correlation between the direct and the bottom-reflected versions of this random function is obtained. For the special case of no attenuation, there is negligible change in the correlation peak when Q > or = 1.5, where Q is the center frequency divided by the bandwidth. The cross-correlation peak is evaluated as a function of the bandwidth in Hz and the attenuation in nepers/Hz. (Author)

Descriptors :   (*UNDERWATER SOUND SIGNALS, DISTORTION), (*SONAR PULSES, REFLECTION), OCEAN BOTTOM, MATHEMATICAL MODELS, STATISTICAL FUNCTIONS, TRANSFER FUNCTIONS

Subject Categories : Acoustic Detection and Detectors
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE