harmonica.gaussian_lowpass

harmonica.gaussian_lowpass(grid, wavelength, *, pad=True, pad_kwargs=None)

Calculate the Gaussian low-pass of a potential field grid.

Compute the Gaussian low-pass of regular gridded data using frequency domain calculations through Fast Fourier Transform.

Parameters:

gridxarray.DataArray

A two dimensional xarray.DataArray whose coordinates are evenly spaced (regular grid). Its dimensions should be in the following order: northing, easting. Its coordinates should be defined in the same units.

wavelengthfloat

The cutoff wavelength in low-pass filter. Its units are the same units of the grid coordinates.

padbool, optional

If True, will add padding to the grid before taking the Fourier Transform and applying the filter and remove it after the inverse Fourier Transform. Adding padding usually helps reduce edge effects from signal truncation. Default is True.

pad_kwargsdict or None, optional

Any additional keyword arguments that should be passed to the xarray.DataArray.pad function in the form of a dictionary. If none are given, the default padding of 25% the dimensions of the grid will be added using the “edge” method.

Returns:

gaussian lowpassxarray.DataArray

A xarray.DataArray after Gaussian low-pass of the passed grid.

See also

harmonica.filters.gaussian_lowpass_kernel

References

[Geosoft1999]