Accession Number : AD0780462

Title :   Some Properties and Effects of Reverberation in Acoustic Surveillance,

Corporate Author : GENERAL ATRONICS CORP PHILADELPHIA PA

Personal Author(s) : Urkowitz,Harry

Report Date : FEB 1967

Pagination or Media Count : 44

Abstract : Reverberation or clutter may be considered as a special case of an extended, randomly varying target causing an echo which is like noise in that it is approximately a Gaussian random process. In the general case, the statistical properties are not easy to interpret physically, but when the scatterer reflectivity does not vary with time, the statistical properties of the clutter are described by its scattering function which is shown to be the joint probability density function of the distribution of scatterers in delay and in doppler frequency shift. If the delay distribution of the scatterers is uniform over an interval equal to the duration of the transmitted waveform, then the clutter may be considered wide-sense stationary, at least locally, so that it is described by a power density spectrum. (Modified author abstract)

Descriptors :   *Acoustic surveillance, *Reverberation, Signal to noise ratio, Acoustic detection, Waveforms, Correlation techniques, Functions(Mathematics), Spectral energy distribution, Signal processing, Statistical analysis

Subject Categories : Acoustic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE