Application of Pure-Tone Atmospheric Absorption Losses to One-Third Octave-Band Data
This document presents a practical method for calculating atmospheric absorption for wide-band sounds analyzed with one-third octave-band filters, called the SAE Method. The SAE Method utilizes pure-tone attenuation algorithms originally published in ISO 9613-1 and ANSI S1.26-1995 to calculate path-length attenuation at mid-band frequencies. The equations introduced in this standard transform the pure-tone, mid-band attenuation to one-third octave-band attenuation. The purpose of this guidance document is to extend the useful attenuation range of the Approximate Method outlined in ANSI S1.26-1995, and to replace ARP866A. Calculation of sound attenuation caused by mechanisms other than atmospheric absorption such as divergence, refraction, scattering due to turbulence, ground reflections, or non-linear propagation effects, is outside the scope of this document.