Band-pass Filter

Use the Band-pass option to apply a Fast Fourier Transform (FFT) band-pass filter to a channel.

The filter option is available with the following extensions and menus:

• 1D FFT > 1D Filtering
• Moving Platform Gravity  > Filters > Apply Single FFT Filter

Band-pass filter options

Short wavelength cutoff (in ground units)	Short wavelength cutoff value (in ground units). Default = 0.1 Script Parameter: FFTBANDP.SHORTW
Long cutoff -> Enter 0 for infinite value	Long wavelength cutoff value. Enter 0 for an Infinite cutoff wavelength (in ground units). Default = 1 Script Parameter: FFTBANDP.LONGW
Pass or reject defined band	Select whether to Pass or Reject the defined band. Default = Pass Script Parameter: FFTBANDP.PASS

Application Notes

This filter can be used to pass or reject a range of wavenumbers from the data. However, applying such a simple cutoff filter to an energy spectrum almost invariably introduces a significant amount of ringing (also known as Gibb's Phenomenon). We recommend using a smoother filter, such as the Butterworth filter.

Band-pass Filter

Parameters:

k₀: Low wavenumber cutoff in cycles/ground unit.

k₁: High wavenumber cutoff in cycles/ground unit.

0/1: If 1, pass the defined band; otherwise, reject the defined band. The default is to pass the band.