invert4geom.DatasetAccessorInvert4Geom.regional_eq_sources

invert4geom.DatasetAccessorInvert4Geom.regional_eq_sources#

DatasetAccessorInvert4Geom.regional_eq_sources(depth='default', damping=None, block_size=None, grav_obs_height=None, cv=False, weights_column=None, cv_kwargs=None, 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 fitting deep equivalent sources to the the gravity misfit, using harmonica.EquivalentSources. During fitting of the equivalent sources, the source depth can be chosen with depth, the results can be smoothed with damping, the gravity points can block-reduced with block_size, and to simulate upward continuation, the gravity observation height can be set with grav_obs_height. Instead of specifying the equivalent source parameters depth and damping, optimal values can be chosen through a cross-validated optimization routine by setting cv to True, and providing cv_kwargs which is passed to the function optimize_eq_source_params.

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:

  • depth (float | str) – depth of each source relative to the data elevation

  • damping (float | None) – smoothness to impose on estimated coefficients, by default None

  • block_size (float | None) – block reduce the data to speed up, by default None

  • grav_obs_height (float | None) – Observation height to use predicting the eq sources, by default None and will use the data height from grav_ds.

  • cv (bool) – use cross-validation to find the best equivalent source parameters, by default False, provide dictionary cv_kwargs which is passed to optimize_eq_source_params and can contain: n_trials, damping_limits, depth_limits, block_size_limits, sampler, plot, progressbar, parallel, dtype, or delayed.

  • weights_column (str | None) – column name for weighting values of each gravity point.

  • 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

See also

DatasetAccessorInvert4Geom.regional_separation, optimize_eq_source_params

Return type:

None

Parameters:

cv_kwargs (dict[str, Any] | None)