Accession Number : ADA269268

Title :   Design of a General Purpose and Autonomous Transmitter and Receiver System for Underwater Acoustic Experiments at Sea.

Descriptive Note : Final rept. 1 Oct 88-30 Sep 92,

Corporate Author : ROSENSTIEL SCHOOL OF MARINE AND ATMOSPHERIC SCIENCE MIAMI FL DIV OF APPLIED M ARINE PHYSICS

Personal Author(s) : Nguyen, Hien ; Deferrari, Harry ; Williams, Neil

Report Date : 31 AUG 1993

Pagination or Media Count : 43

Abstract : A versatile multi-frequency, multi-purpose acoustic transmitter and receiver system has been developed and used to measure low frequency acoustic backscatter from the ocean wave surface. The instrumentation is general purpose in that all signal and sample parameters are selected by software and a variety of transmission, scattering and reverberation experiments are possible without hardware modification. The system is battery-powered and self-contained for remote and unattended operation for periods of months, depending upon the experimental parameters that affect power and tape consumption. The main features of the system are: a high powered broadband set of acoustic sources-with center frequencies of 100, 200, 400, and 800 Hz, programmable output signal types, a 64 element vertical hydrophone array, twenty gigabytes of data storage capacity, dynamically-tuneable band pass filters and variable sampling rates, high power microprocessors for in-situ signal processing and independent subsystems for recording mooring depth and inclination. The system has been used in surface backscattering experiments at sea and results that demonstrate the capability of the system are presented and discussed.... Underwater acoustics, Instrumentation, Surface backscatter

Descriptors :   *HYDROPHONES, *RECEIVERS, *TRANSMITTERS, *UNDERWATER ACOUSTICS, *ACOUSTIC SIGNALS, *SONAR TRANSDUCERS, ARRAYS, BACKSCATTERING, BROADBAND, DEPTH, FILTERS, HIGH POWER, INSTRUMENTATION, LOW FREQUENCY, MICROPROCESSORS, MODIFICATION, MOORING, OCEAN WAVES, REVERBERATION, SAMPLING, SELF CONTAINED, SIGNAL PROCESSING, VARIABLES, ACOUSTIC SCATTERING, OCEAN SURFACE, WIND VELOCITY, AIR WATER INTERACTIONS.

Subject Categories : Acoustic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE