harmonica.filters.upward_continuation_kernel
harmonica.filters.upward_continuation_kernel¶
- harmonica.filters.upward_continuation_kernel(fft_grid, height_displacement)[source]¶
Filter for upward continuation in frequency domain
Return a
xarray.DataArraywith the values of the frequency domain filter for computing the upward continuation. The filter is built upon the frequency coordinates of the passedfft_gridand is defined as follows:\[g(\mathbf{k}) = e^{-|\mathbf{k}| \Delta h}\]where \(\mathbf{k}\) is the wavenumber vector (\(\mathbf{k} = 2\pi \mathbf{f}\) where \(\mathbf{f}\) is the frequency vector) and \(\Delta h\) is the height displacement of the upward continuation.
- Parameters
fft_grid (
xarray.DataArray) – Array with the Fourier transform of the original grid. Its dimensions should be in the following order: freq_northing, freq_easting. Usexrft.xrft.fftandxrft.xrft.ifftfunctions to compute the Fourier Transform and its inverse, respectively.height_displacement (float) – The height displacement of upward continuation. For upward continuation, the height displacement should be positive. It has the same units as the input xarray data coordinates.
- Returns
da_filter (
xarray.DataArray) – Array with the kernel for the upward continuation filter in frequency domain.
References
See also