Accession Number : ADA301331

Title :   Further Sensitivity Studies of Community-Aircraft Noise Exposure (NOISEMAP) Prediction Procedures.

Descriptive Note : Final rept.,

Corporate Author : BOLT BERANEK AND NEWMAN INC CANOGA PARK CA

Personal Author(s) : Bishop, Dwight E. ; Mills, John F. ; Dunderdale, Thomas C. ; Horonjeff, Richard D.

PDF Url : ADA301331

Report Date : APR 1977

Pagination or Media Count : 88

Abstract : This report describes the results of studies of the sensitivity of the noise exposure contours to various model parameters and assumptions presently in the NOISEMAP procedure. The areas within Day/Night Level (LDN) contours for ten Air Force airbases increased by 11 to 4O percent when the noise measure was adjusted for the presence of pure tones. The contour areas for typical mixed fighter, bomber/tanker, and training airbases were reduced by 3 to 11 percent by substitution of the SAE algorithms for ground-to-ground propagation and transition models, whereas adding the fuselage shielding algorithm reduced the contour areas by 13 to 22 percent. Since there is little firm evidence showing one set of algorithm more accurate than the other, the present NIOISEMAP models will be retained until further technical analyses or new data show a clear basis for alteration. The contour areas for typical National Guard and combined bomber/tanker/fighter airbases for standard day weather conditions were reduced by up to 10 percent using sumner-type climate conditions, but were reduced by 18 to 60 percent by winter weather conditions. Although use of standard dry conditions results in contours that are quite representative for most bases, it is recommended that contours be developed based on a simple review of the absorption coefficients (for the 1000 Hz one-third octave frequency band) determined from the set of monthly average temperatures and relative humidities.

Descriptors :   *SENSITIVITY, *SURVEYS, *AIRCRAFT NOISE, *COMMUNITY RELATIONS, ALGORITHMS, NATIONAL GUARD, PROPAGATION, MEASUREMENT, MILITARY FACILITIES, WEATHER, COMMUNITIES, PREDICTIONS, EXPOSURE(GENERAL), MODELS, TRAINING, PARAMETERS, VARIATIONS, WINTER, CLIMATE, DAY, JET FIGHTERS, NIGHT, TRANSITIONS, NOISE, NUMERICAL METHODS AND PROCEDURES, AIRPORTS, ABSORPTION COEFFICIENTS, AUDIO TONES, SURFACE TO SURFACE, CONTOURS.

Subject Categories : Bombers
      Attack and Fighter Aircraft
      Sociology and Law
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE