Accession Number:

ADA276476

Title:

A Preliminary Study of Shallow-Water Sonar Issues: Signal Motion Loss and Reverberation Noise

Descriptive Note:

Technical rept.

Corporate Author:

WOODS HOLE OCEANOGRAPHIC INSTITUTION MA

Report Date:

1993-09-01

Pagination or Media Count:

56.0

Abstract:

This preliminary investigation addresses key program elements for sonar sensing in a shallow-water environment to establish bounds on possible solutions and to reduce program uncertainty. The modeling and experimental program focuses on two issues-the potential degradation of sonar data due to signal masking by shallow-water reverberation and signal loss caused by extreme platform motions. The research program combines theoretical analysis, experimental validation in a shallow-water environment, and development of a computer model to explore parametric sensitivity. Results from an initial dock- side test show good agreement with the theoretical predictions. From the shallow-water experiments and acoustic modeling we conclude that 1 Signal motion loss can influence the reverberation level significantly but is not the dominant factor in target detection for sonars in the frequency range of interest 200 kHz a high-quality velocity-aided inertial navigation and attitude system will be sufficient to correct for geometric distortions caused by platform motion. 2 Although surface reverberation and multipath noise can be a factor, particularly in shadow-mode imaging, reverberation levels are rapidly attenuated at the frequencies of interest and beam patterns can be manipulated to reject most interferences echo-mode imaging is still dominated by the contrast between target strength and bottom reverberation. Shallow-water acoustics, Target detection, Sonar modeling.

Subject Categories:

  • Acoustic Detection and Detectors

Distribution Statement:

APPROVED FOR PUBLIC RELEASE