API Reference

Harmonica: Processing and modelling gravity and magnetic data.

Gravity Corrections

bouguer_correction(topography[, ...])

Gravitational effect of topography using a Bouguer plate approximation.

For the Normal Earth correction, see package boule.

Grid Transformations

Apply well known transformations regular gridded potential fields data.

derivative_easting(grid[, order, method])	Calculate the derivative of a regular grid in the easting direction.
derivative_northing(grid[, order, method])	Calculate the derivative of a regular grid in the northing direction.
derivative_upward(grid[, order])	Calculate the derivative of a potential field grid in the upward direction.
upward_continuation(grid, height_displacement)	Calculate the upward continuation of a potential field grid.
gaussian_lowpass(grid, wavelength)	Calculate the Gaussian low-pass of a potential field grid.
gaussian_highpass(grid, wavelength)	Calculate the Gaussian high-pass of a potential field grid.
reduction_to_pole(grid, inclination, declination)	Calculate the reduction to the pole of a magnetic field grid.
total_gradient_amplitude(grid)	Calculate the total gradient amplitude of a potential field grid.
tilt_angle(grid)	Calculate the tilt angle of a potential field grid.

Frequency domain filters

Define filters in the frequency domain.

filters.derivative_easting_kernel(fft_grid)	Filter for easting derivative in frequency domain.
filters.derivative_northing_kernel(fft_grid)	Filter for northing derivative in frequency domain.
filters.derivative_upward_kernel(fft_grid[, ...])	Filter for upward derivative in frequency domain.
filters.upward_continuation_kernel(fft_grid, ...)	Filter for upward continuation in frequency domain.
filters.gaussian_lowpass_kernel(fft_grid, ...)	Filter for Gaussian low-pass in frequency domain.
filters.gaussian_highpass_kernel(fft_grid, ...)	Filter for Gaussian high-pass in frequency domain.
filters.reduction_to_pole_kernel(fft_grid, ...)	Filter for reduction to the pole in the frequency domain.

Use xrft.xrft.fft and xrft.xrft.ifft to apply Fast-Fourier Transforms and its inverse on xarray.DataArray.

Equivalent Sources

EquivalentSources([damping, points, depth, ...])	Equivalent sources for generic harmonic functions (gravity, magnetics).
EquivalentSourcesGB([damping, points, ...])	Gradient-boosted equivalent sources for generic harmonic functions.
EquivalentSourcesSph([damping, points, ...])	Equivalent sources for generic harmonic functions in spherical coordinates.

Forward modelling

Gravity fields:

point_gravity(coordinates, points, masses, field)	Compute gravitational fields of point masses.
prism_gravity(coordinates, prisms, density, ...)	Gravitational fields of right-rectangular prisms in Cartesian coordinates.
tesseroid_gravity(coordinates, tesseroids, ...)	Compute gravitational field of tesseroids on computation points.

Magnetic fields:

dipole_magnetic(coordinates, dipoles, ...[, ...])	Magnetic field of dipoles in Cartesian coordinates.
prism_magnetic(coordinates, prisms, ...[, ...])	Magnetic field of right-rectangular prisms in Cartesian coordinates.

Layers and meshes:

prism_layer(coordinates, surface, reference)	Create a layer of prisms of equal size.
tesseroid_layer(coordinates, surface, reference)	Create a layer of tesseroids of equal size.
DatasetAccessorPrismLayer(xarray_obj)	Defines dataset accessor for layer of prisms.
DatasetAccessorTesseroidLayer(xarray_obj)	Define dataset accessor for layer of tesseroids.

Isostatic Moho

isostatic_moho_airy(basement[, layers, ...])

Calculate the isostatic Moho depth using Airy's hypothesis.

Source position estimation

EulerDeconvolution(structural_index)

Estimate source location and base level using Euler Deconvolution.

Spherical Harmonics

IGRF14(date[, min_degree, max_degree, ellipsoid])

International Geomagnetic Reference Field (14th generation).

Input and Output

load_icgem_gdf(fname, **kwargs)	Read data from an ICGEM .gdf file.
load_oasis_montaj_grid(fname)	Read gridded data from an Oasis Montaj© .grd file.

Visualization

visualization.prism_to_pyvista(prisms[, ...])

Create a pyvista.UnstructuredGrid out of prisms.

Utilities

magnetic_vec_to_angles(magnetic_e, ...[, ...])	Convert magnetic field vector to magnetic field angles.
magnetic_angles_to_vec(intensity, ...)	Convert magnetic field angles to magnetic field vector.
total_field_anomaly(magnetic_field, ...)	Compute the total field anomaly from the anomalous magnetic field.