The Sinefit Spectral Envelope Preprocessor

This paper presents a new spectral envelope preprocessor based on sinusoid fitting and the discrete Fourier transform. This preprocessor is well-suited for nonintrusive condition monitoring and diagnostics due to its high noise resiliency and flexibility. It reduces data storage, transfer, and processing requirements by extracting only relevant harmonic signatures. This paper analyzes the resolution and accuracy benefits of spectral envelopes, including the effects of additive white Gaussian noise and presence of higher frequency spectral harmonics.