Application of Time-Localized Spectral Analyses (S-Transform) to Multi-Emission, All-Sky Image Data of Mesospheric Gravity Waves

Northwest Research Associates, Incorporated, Seattle WA

Investigators

Abstract

A novel analysis algorithm, the "S-Transform", is applied to all-sky images of emissions from the mesosphere and lower thermosphere to extract the gravity wave spectral signatures of frequency and horizontal and vertical wavenumber. The S-transform is a Time Frequency Representation (TFR) technique capable of identifying transient wave packets characteristic of coherent wave features in the airglow. The algorithm expanded from the current 1-dimensional form to a 4-dimensional form (time, XY horizontal, and vertical). Algorithm testing and validation is provided by a supply of actual all-sky data acquired by collaborative formality from Utah State University.