Accession Number : ADA137292

Title :   Technical Specifications for Spread Function Model.

Corporate Author : SCIENCE APPLICATIONS INC MCLEAN VA

PDF Url : ADA137292

Report Date : May 1983

Pagination or Media Count : 48

Abstract : In order to design and accurately estimate the performance of a candidate passive sonar system the systems engineer needs considerably more information than the standard terms in the passive sonar equation. The sonar equation typically deals with the mean values of the total signal and noise fields. All departures from these means are considered only in the time domain as fluctuations in signal excess which lead to the probabilistic description of the detection process in terms of ROC curves, etc. As a first refinement of this approach, still in the mean value sense however, a higher resolution description of these fields is sought. In order to estimate array signal gain, processor gain, and detection and localization performance additional information beyond these means is required on the spreads of these values. This paper addresses the technical specifications for a set of models to support these requirements. For this treatment only second moments (distributions for angles, decorrelation times, frequency spreads) will be considered. While higher-order moments are desirable, their general treatment is beyond the scope of the present effort. In some special cases, such as the distribution of intensity (a collapsed fourth-order moment), estimates may be possible and are considered.

Descriptors :   *Acoustic signals, *Acoustic attenuation, *Spread spectrum, *Passive sonar, Signal processing, Signal to noise ratio, Specifications, Mean free path, Ambient noise, Doppler effect, Frequency, Time domain, Vertical orientation, Horizontal orientation, Angle of arrival, Acoustic waves, Surface waves, Shallow water, Bottom loss, Mathematical models, Data acquisition

Subject Categories : Acoustic Detection and Detectors
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE