Spectral Signature

"This refers to the particular form or shape evinced by the power spectrum calculated from the data comprising the time series of a process." (National Aeronautics and Space Administration, 2017)

Sources

"Glossary". Earth Observatory, National Aeronautics and Space Administration. Last modified August 4, 2017.
https://www.earthobservatory.nasa.gov/glossary/all.
Accessed February 14, 2019.