Your Search Results

Use this resource - and many more! - in your textbook!

AcademicPub holds over eight million pieces of educational content for you to mix-and-match your way.

Experience the freedom of customizing your course pack with AcademicPub!
Not an educator but still interested in using this content? No problem! Visit our provider's page to contact the publisher and get permission directly.

An Acoustic System for Measuring Ocean Flows by Space-Time Scintillation Analysis

By: Lemon, D.; Farmer, D.; Chave, R.; Knight, D.;

1987 / IEEE

Description

This item was taken from the IEEE Periodical ' An Acoustic System for Measuring Ocean Flows by Space-Time Scintillation Analysis ' We describe an acoustic measurement system built to test several techniques for analyzing a forward-scattered sound field in the ocean. The fluctuations of the sound field contain information about the field of flow along the acoustic path. The instrument consists of a microprocessor-controlled, radio-linked transmitter with a 4-element array, a 4-element receiving array and a receiver incorporating signal processing, data logging and control electronics on a VME bus. Pseudo-random noise coding is used to enhance the signal, with the decoding being carried out in real time by a high-speed multichannel hardware correlator.The transmit and receive arrays may be configured to test spatial aperture filtering for measuring the mean flew field or to measure the structure function of the refractive-index turbulence. Dual-frequency operation is also available for differential absorption measurements. Preliminary results of a field test in a turbulent tidal channel are presented.