title: Noise duration for a single overflight.
abstract: Overflights in national parks and preserves interfere with communication and sounds of nature. The percentage of time that an aircraft is audible, P, can be used as a noise metric. To calculate P the overflight time for a single aircraft, tau, has to be known. The method of tau calculation is based on the assumption that an aircraft is a point source and the noise propagation is governed by geometrical spreading, air absorption, and refraction. The atmosphere is characterized by the effective sound speed gradient. Analytical formulas for tau are derived for down- and crosswind flights.
authors.affiliation: Institute of Acoustics, A. Mickiewicz University, 61-614 Poznan, Umultowska 85, Poland. makaaku@amu.edu.pl
authors.forename: Rufin
authors.initials: R
authors.lastname: Makarewicz
authors.forename: Hanna
authors.initials: H
authors.lastname: Wojciechowska
mesh_terms: D000054:Acceleration; D000162:Acoustics; D000401:Aircraft; D001272:Atmosphere; D006801:Humans; D008962:Models, Theoretical; D009624:Noise, Transportation / Q000706:statistics & numerical data*; D013018:Sound Spectrography; D013997:Time Factors