A sensitivity study of NOISEMAP power offset profiles

The USAF NOISEMAP computer program uses measured noise data for each aircraft in the inventory at selected reference power settings and airspeeds together with operational data for a given installation to predict noise exposure contours near the installation. The contribution from aircraft flying at other than reference conditions to the contours is computed through the use of offset profiles. The influence of offset profiles on noise contours was studied for seven bases selected to be representative of various aircraft type and operational situations. All computer runs made were for a complete set of actual operations for the bases chosen. Runs with actual-, modified-, and zero-power offset profies were made for each base. The simulations indicate that offset profiles may be important for only the statistically dominant aircraft at a base. [Work supported by USAF OSR.]