Notch (NOTCH)

Use the Notch option to apply the notch filter.

Notch Filter dialog options

Central wavelength	Central wavelength to reject, in ground units.
Power factor	The larger the power the wider the rejected band. (Default=1).
Depth factor	The smaller the depth factor, the more abrupt the rejection band (default = 2).

Application Notes

The Notch filter allows to reject the desired mid-wavenumber range while maintaining the low and high extremes of the wavenumber continuum. The Power controls how wide the rejection bad is; the Depth factor controls the degree of the abruptness of the wave form operator.

Notch Filter

Where:

k0	Cutoff wavenumber in cycles/ ground unit.
n	Power of the filter function
q	Degree of the filter function

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.