Accession Number : ADA296304

Title :   Source Level Calibration of the DREA Moving Coil Projector.

Descriptive Note : Technical memo,

Corporate Author : DEFENCE RESEARCH ESTABLISHMENT ATLANTIC DARTMOUTH (NOVA SCOTIA)

Personal Author(s) : Osler, John C. ; Chapman, David M.

PDF Url : ADA296304

Report Date : MAY 1995

Pagination or Media Count : 35

Abstract : SOUND GENERATORS,The Defence Research Establishment Atlantic moving coil projector (MCP) generates acoustic power at low frequencies (below 250 Hz) by displacing water with two pistons which oscillate in phase. The source level of the MCP must be continually monitored because it varies in accordance with the operating state of the projector. Source level as a function of time may be determined by combining measurements of the acceleration of the forward and aft pistons in an appropriate manner. This document establishes the methodology to use in this process by comparing at sea measured transmission loss of CW signals to theoretical calculations. This comparison reveals that corrections are required to the source level derived from the MCP accelerometers at the higher end of its frequency range.

Descriptors :   *SONAR PROJECTORS, METHODOLOGY, PISTONS, COILS, COMPUTATIONS, ACCELEROMETERS, CANADA, MOTION, ACOUSTICS, POWER, CALIBRATION, UNDERWATER ACOUSTICS, TRANSMISSION LOSS, LOW FREQUENCIES.

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE