Accession Number : ADA293101

Title :   Seasonal Sonic Boom Propagation Prediction.

Descriptive Note : Final rept. Sep 91-Oct 92,

Corporate Author : ARMSTRONG LAB BROOKS AFB TX OCCUPATIONAL AND ENVIRONMENTAL HEALTH DIRECTORATE

Personal Author(s) : Lundberg, W. R.

PDF Url : ADA293101

Report Date : MAR 1994

Pagination or Media Count : 61

Abstract : Seasonal variations in wind and temperature gradients are known to influence the propagation of sonic booms. This report examines predictive techniques in current use which may be refined for application to seasonal Environmental Impact Statements. The effects of seasonally averaged refractive atmospheres on the sonic boom carpet predictions for an example flight of an F-111 at Mach 1.3 and 10,000 feet above Mean Sea Level (MSL) were documented. The effect of such atmospheres on predicted noise exposures due to a real-world mix of supersonic flights was estimated. The example boom environment was chosen to be that near Edwards Air Force Base (EAFB) where sonic booms are known to affect the public. Two distinct atmospheric averaging techniques were applied seasonally and the resulting sonic boom predictions compared to each other and to those predictions obtained using the U.S. Standard Day Atmosphere and the Annual reference Atmosphere for Edwards AFB. The results show the potential benefit of conducting seasonal sonic boom predictions in forecasting the effects which supersonic flight operations have on the public. (AN)

Descriptors :   *ACOUSTIC WAVES, *NOISE POLLUTION, *SONIC BOOM, MATHEMATICAL MODELS, EXPERIMENTAL DATA, COMPARISON, SEASONAL VARIATIONS, TEMPERATURE GRADIENTS, MATHEMATICAL PREDICTION, WAVE PROPAGATION, WIND VELOCITY, SUPERSONIC FLIGHT, EXPOSURE(PHYSIOLOGY), ALTITUDE, ATMOSPHERIC REFRACTION, ENVIRONMENTAL IMPACT STATEMENTS, AIRCRAFT NOISE, ACOUSTIC REFRACTION, SOUND RANGING.

Subject Categories : Acoustics
      Noise Pollution and Control

Distribution Statement : APPROVED FOR PUBLIC RELEASE