Apparent Density Calculation Filter

Use the Apparent Density Calculation option to apply a Fast-Fourier Transform Apparent Density filter to a channel.

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

  • Geophysics: 1D FFT > 1D Filtering
  • Gravity and Terrain Correction: Moving Platform Gravity  > Apply Single FFT Filter

Apparent Density Calculation filter option

Depth to the top of model

Depth to the top of the model. Default = 1

Script Parameter: FFTDENS.DEPTH

Thickness of earth model

Thickness of earth model. Default = 1

Script Parameter: FFTDENS.THICK

Low-pass cutoff
(in ground units)

Low-pass Butterworth filter cutoff wavelength. Default = 1

Script Parameter: FFTDENS.LP

Background Density
(g/cm3)

Background density (g/cm3). Default = 0

Script Parameter: FFTDENS.DENS

Application Notes

In order to have correct density units, the input data fiducial base must be in metres. The low-pass filter can be used to remove noise in the data that would be amplified by the downward continuation. A low-pass cutoff of 1 to 1.5 times the depth is normally appropriate.

Apparent Density Filter

image\ebx_1569821416.jpg

Parameters:

t Thickness, in ground_units, of the earth model.
d Background density in g/cm3
G Gravitational constant.