Characteristics of aircraft sound propagation from high altitude

摘要

This paper introduces analysis result of aircraft sound propagation characteristics from high altitude to the ground. Many aircraft fly high altitude route (higher than 3 km / 10,000 ft) over the west side of Tokyo, because there are some flight routes which climbing to en-route after taking off from Haneda airport. Aircraft sound propagating from high altitude is low noise level but aircraft noise from such high altitude may be heard at a quiet environment such as night time. The high altitude flight noise was not generally subject to aircraft noise measurement carried out around airport, so there were few cases of measurement. In order to grasp aircraft sound propagation characteristic from high altitude, noise measurement from aircraft flying high altitude (5 km to 9.5 km) was carried out. In addition, momentary flight position and altitude of aircraft were collected by ADS-B (Automatic Dependent Surveillance - Broadcast) synchronized with the noise measurement. Time histories of A-weighted and 1/3 octave band sound pressure level of high altitude aircraft sound were analyzed in accordance with aircraft position.