Error probability in spectral analysis using DFT or FFT analyzers

The arbitrary use of weighting functions, large frequency spans or preselection of averages in low amplitude signals analysis without consideration for the type of signal or the area of interest, e.g., tones, rolloff, etc. can produce uncertainties when qualifying systems for performance. These uncertainties or errors, can be analyzed for trends and qualitative levels attached that will provide an understanding of these signals that can be applied to other systems under analysis.