Bandpass (BPAS)

Use the Bandpass option to apply a bandpass filter.

Bandpass Filter dialog options

Long wavelength cutoff

The long wavelength cutoff in ground unit. See illustration, this parameter is equivalent to k0-1.

Short wavelength cutoff

The short wavelength cutoff in ground unit. See illustration, this parameter is equivalent to k1-1.

Pass

Reject

Pass or reject the defined band; The default is to pass the band.

Application Notes

The bandpass filter (BPAS) can be used to pass or reject a range of wavelengths contained in the data. However, applying such a simple cutoff filter operator to an energy spectrum almost invariably introduces a significant amount of oscillation (also known as Gibbs’ Phenomenon). This filter is present for the sake of completeness. We recommend that you use a tapered filter such as the Butterworth filter (BTWR).

Bandpass Filter

Where:

k0

Low wavenumber cutoff in cycles/ ground unit.

k1

High wavenumber cutoff in cycles/ground unit.
Wavenumber domain variable definition
 

k

Wavenumber domain increment, used to depict a radially symmetrical variable.

where:

np is the number of points

cs is the cell size

u

X component in the wavenumber domain. k = 2π ( i μ+j ν )

v

Y component in the wavenumber domain.

 

r

Radial component in the wavenumber domain.

also 2πk

θ

Polar component in the wavenumber domain.

  • Ground_unit is the survey ground units as defined in your grid (e.g. metre or feet). Ground units may be left undefined.