*********** +++++++++++++++++++++ 101695B.OAC + Source: ONR Asia + *********** +++++++++++++++++++++ Contributory Categories: Country: Australia From: DSTO Aeronautical and Maritime Research Laboratory PO Box 4331 Melbourne Victoria 3001 DSTO-GD-0023 KEYWORDS: Australia; Ocean Acoustics, Computer Manual, Fortran, Ship Noise +++++ MANUAL FOR THE PROGRAM B&KNOISE (version 2.0) Sandra Tavener Maritime Operations Division Aeronaufical and Maritime Research Laboratory ABSTRACT The installation, control and outputs of the program B&KNOISE are described. B&KNOISE is a program designed to analyse sea noise or any other quasi-stationary signal. The program was designed to be user friendly and uses menus to take the operator through the analysis stages. Control of a Bruel and Kjaer 2131 spectrum analyser is handled by B&KNOISE and calculation of the mean and standard deviation are also performed by the program. The output is a number of files that contain the calculated information. Graphs can also be produced by the program. Published by DSTO Aeronautical and Maritime Research Laboratory PO Box 4331 Melbourne Victoria 3001 Telephone: (03) 9626 8111 Fax: (03) 9626 8999 @ Commonwealth of Australia 1995 AR No. 008-935 July 1995 APPROVED FOR PUBLIC RELEASE CONTENTS 1. Introduction 2. Operating instructions 2.1 System Requirements 2.2 Installation Computer interface to the spectrum analyser Input signal to the spectrum analyser Program B&KNOISE 3. Principles of sea noise measurement 3.1 Generalised Sea Noise Measurement Setup 3.2 Calibration Signals 3.3 Sea Noise Measurement 3.4 Calculations 4. Menus 4.1 Main Menu Check/change measurement options Calibration Sea noise Graph sea noise versus frequency or time Print sea noise and standard deviations Quit 4.2 Measurement Options Number of frequency channels used on B & K 2131 First channel number used on B & K 2131 Averaging Time (s) Number of samples per block Total number of blocks Time between each block (s) Cal source, none (N), white (W) or pink (P) noise Calibration Source Level (dB re lV2/Hz lkhz) Hydrophone sensitivity file Calibration Gain (dB) Sea Noise Gain (dB) Tape Label (nnn/dd/mm/yy) Play tape recorder plant number Graphics files? (Y/N) Main output file name E: Exit From Routine / C: Change An Entry 4.3 Calibration 4.4 Sea Noise 4.5 Graph Menu Graph mean levels versus frequency Graph mean levels versus time Return to main menu 4.6 Print Sea Noise And Standard Deviations 4.7 Quit 5. Input files 6. Output files Appendix A - Default values file Appendix B - Hydrophone Sensitivity File Appendix C - Output File Examples Appendix D - Graphs Available 1. Introduction B&KNOISE is an ambient sea noise processing program designed to be user friendly. Although it was developed specifically for the analysis of sea noise it could be used for the analysis of any other quasi-stationary signal. The program works by setting up and controlling the Bruel and Kjaer spectrum analyser according to choices made by the operator. Choices are made through menus and encourage the operator to go through the stages in a particular order. After the setup is complete B&KNOISE triggers the spectrum analyser to sample over the selected averaging time in one third octave bands. The detected levels on the spectrum analyser are passed on to the computer where the mean and standard deviation are calculated and stored in file form. Many measurements of noise spectra, at fixed time intervals, are possible. B&KNOISE was written by Sandra Tavener, mainly using the language Nficrosoft FORTRAN V5.0. A small routine was written in Microsoft C V6.0 to determine if the keyboard was struck. In FORTRAN V5.0 this function was not possible without either displaying a character on the screen or interrupting the processing of B&KNOISEUsing C V6.0 it was possible to perform this function totally in the background. CMR Disclaimer================================================== This document could contain information all or part of which is or may be copyrighted in a number of countries. Therefore, commercial copying and/or further dissemination of this text is expressly prohibited without obtaining the permission of the copyright owner(s) except in the United States and other countries for certain personal and educational uses as prescribed by the "fair copy" provisions of that countries Copyright Statues. ================================================================ ************** END Msg. B.OAC **************