invert4geom.DatasetAccessorInvert4Geom.regional_filter

invert4geom.DatasetAccessorInvert4Geom.regional_filter#

DatasetAccessorInvert4Geom.regional_filter(filter_width, filter_type='lowpass', regional_shift=0, mask_column=None, reverse_regional_residual=False)[source]#

Calculate the gravity misfit as the difference between dataset variables gravity_anomaly and forward_gravity. Then separate the misfit into regional and residual components where residual = misfit - regional.

Approximate the regional field by filtering the gravity misfit with a low-pass gaussian filter with a supplied filter width, using harmonica.gaussian_lowpass. The grid will automatically be padded to reduce edge effects.

The resulting regional field can be shifted with regional_shift, and the calculated residual field can be multiplied by the values in mask_column.

The following new variables are added to the dataset:

misfit, reg, res, starting_forward_gravity, starting_misfit, starting_reg, starting_res

Parameters:
  • filter_width (float) – width in meters to use for the low-pass filter

  • filter_type (str) – type of filter to apply, by default “lowpass”

  • regional_shift (float) – shift to add to the regional field, by default 0

  • mask_column (str | None) – Name of optional dataset variable with values to multiply the calculated residual gravity field by, should have values of 1 or 0, by default None.

  • reverse_regional_residual (bool) – if True, reverse the regional and residual fields after calculation, by default False

Return type:

None