Low-frequency source characterization of aircraft noise during landing operations

摘要

Low-frequency noise emission by commercial aircraft is of particular interest due to the minimalattenuation of these frequencies by barriers and atmospheric absorption. Furthermore, noisemodeling software such as the Integrated Noise Model (INM) does not currently model noiseemissions below 50 Hz. The current study characterizes source noise during landings tofacilitate more-accurate modeling of community impact. Recordings of aircraft landingoperations were made with a widely spaced microphone array positioned near and parallel to the19R runway at Washington-Dulles International Airport in October 2004. In addition, thelandings were recorded with a video camera to obtain positional data of the aircraft. Given anaircraft’s position and velocity along the runway, the signal at each microphone is corrected forretarded time, spherical spreading, atmospheric absorption, and Doppler shift. Individualmicrophone signals are combined to determine level and directivity overall and in third-octavebands in the INM frequency range 50 Hz - 10 kHz, and to calculate spectra at lower frequencies(10 Hz – 63 Hz). Aircraft studied ranged from regional (e.g. Bombardier CL600) to highcapacity,long-distance jets (e.g. Airbus 330). Results for the Boeing 777 and the Airbus 320 arepresented here.