FFT Pre-process

Use the 1D FFT > Advanced Settings > Preprocess menu option (FFTPREP GX) to apply FFT pre-processing procedures to a channel so that the pre-processed channel may be visually inspected.

FFT Preprocess dialog options

Channel to filter	Input channel to be processed. Script Parameter: FFTPREP.IN
Output pre-processed channel	Output pre-processed channel. Script Parameter: FFTPREP.OUT

Application Notes

This GX only creates a channel for the purpose of displaying the channel in case the user wishes to see what the pre-processed function looked like. The FFT processing steps apply the pre-processing steps automatically.

FFT pre-processing procedures include:

• removing a first order trend from the data.
• lengthening the channel to a power-of-2.
• filling the holes using a predictive filter.