Predicting changes in area exposed to aircraft noise

Sets of numerically generated noise exposure contours are available for the vicinity of most domestic Air Force Bases and many civilian airports. For such bases, a simple method for manually predicting the change in area enclosed by a given noise exposure contour is described. Such predictions are used for determining whether or not a full scale computer rerun is necessary for a given set of operational changes. The method proposed involves first estimating the change in contour value for a given point and then using that change in contour value to estimate the change in area enclosed by a given contour. The results of several full scale computer runs using the USAF NOISEMAP computer program to test the proposed method are presented. [Work supported by USAF OSR.]