Accession Number : ADA191289

Title :   Overground Excess Sound Attenuation (ESA). Volume 1. Experimental Study for Flat Grassy Terrains.

Descriptive Note : Final rept. Jul 79-Jun 87,

Corporate Author : HARRY G ARMSTRONG AEROSPACE MEDICAL RESEARCH LAB WRIGHT-PATTERSON AFB OH

Personal Author(s) : Powell, Robert G

PDF Url : ADA191289

Report Date : Jun 1987

Pagination or Media Count : 702

Abstract : This is Volume 1 of a 3 volume series concerning overground excess sound attenuation, ESA, i.e. all attenuation in excess of air absorption and inverse square law effects. All three volumes concern a 15-month study conducted at Wright-Patterson Air Force Base, Ohio, over flat, grassy terrain. Volume 1 describes the study and presents the acoustic and meteorological data base that Volumes 2 and 3 use to formulate ESA functions. The study is described in terms of propagation path,instrumentation, reference noise levels, data acquisition techniques, calibration procedures, the noise source and its location. A large portion of this report is devoted to two appendices. Appendix A contain one-third octave band sound pressure levels, overall and A-weighted levels for 415 events. The noise data come from 10 microphones spaced along a 2400 M propagation path. Appendix B lists one-third octave band, overall and A-weighted ESA values in dB. Also included in this appendix are measures of temperature, relative humidity, wind velocity, wind vector relative to source-receiver position, temperature and wind gradients, and meteorological observations, the data in this volume was used to develop a new USAF ESA model which is presented in Volume 3.

Descriptors :   *ACOUSTIC ATTENUATION, ACOUSTIC DATA, AIR, CALIBRATION, DATA ACQUISITION, DATA BASES, GRADIENTS, HUMIDITY, INVERSION, LEVEL(QUANTITY), METEOROLOGICAL DATA, METEOROLOGY, METHODOLOGY, POSITION(LOCATION), RECEIVERS, WIND, WIND VELOCITY, GROUND LEVEL, ACOUSTIC ABSORPTION, VEGETATION, ORIENTATION(DIRECTION), NOISE(SOUND), TABLES(DATA)

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE