Artemis I launch noise spectra: Effects of variable weather profiles over short- and long-range propagation paths

Abstract

NASA’s Space Launch System (SLS) launched the Artemis I mission at 1:47 am local time on November 16, 2022. The timing of the night launch offered a multitude of interesting weather effects over the propagation paths to measurement locations ranging from 1.5 km to 60 km. This presentation discusses spectra at different distances from Launch Complex 39B, both inside and outside the Kennedy Space Center perimeter. Preliminary analysis of the SLS sound pressure levels and spectra suggests many propagation phenomena are at play. In addition to geometric spreading, atmospheric absorption, and nonlinear propagation, complex weather profiles and ground effects are discussed. Initial results of a single-frequency Greens-function parabolic equation model, with estimated weather profiles along the propagation paths, will be offered with approximate source and receiver height to compare levels at several locations.