Add more FFT-based transformations and filters

doc/api/index.rst

@@ -25,7 +25,13 @@ Apply well known transformations regular gridded potential fields data.
 .. autosummary::
     :toctree: generated/
 
+    derivative_easting
+    derivative_northing
     derivative_upward
+    upward_continuation
+    gaussian_lowpass
+    gaussian_highpass
+    reduction_to_pole
 
 Frequency domain filters
 ------------------------
@@ -35,7 +41,13 @@ Define filters in the frequency domain.
 .. autosummary::
     :toctree: generated/
 
+    filters.derivative_easting_kernel
+    filters.derivative_northing_kernel
     filters.derivative_upward_kernel
+    filters.upward_continuation_kernel
+    filters.gaussian_lowpass_kernel
+    filters.gaussian_highpass_kernel
+    filters.reduction_to_pole_kernel
 
 Use :func:`xrft.xrft.fft` and :func:`xrft.xrft.ifft` to apply Fast-Fourier
 Transforms and its inverse on :class:`xarray.DataArray`.

doc/references.rst

@@ -9,12 +9,14 @@ References
 .. [Dampney1969] Dampney, C. N. G. (1969). The equivalent source technique. Geophysics, 34(1), 39–53. doi:`10.1190/1.1439996 <https://doi.org/10.1190/1.1439996>`__
 .. [Forste_etal2014] Förste, Christoph; Bruinsma, Sean.L.; Abrikosov, Oleg; Lemoine, Jean-Michel; Marty, Jean Charles; Flechtner, Frank; Balmino, G.; Barthelmes, F.; Biancale, R. (2014): EIGEN-6C4 The latest combined global gravity field model including GOCE data up to degree and order 2190 of GFZ Potsdam and GRGS Toulouse. GFZ Data Services. doi:`10.5880/icgem.2015.1 <http://doi.org/10.5880/icgem.2015.1>`__
 .. [Fukushima2020] Fukushima, T. (2020). Speed and accuracy improvements in standard algorithm for prismatic gravitational field. Geophysical Journal International. doi:`10.1093/gji/ggaa240 <https://doi.org/10.1093/gji/ggaa240>`__
+.. [Geosoft1999] Geosoft Incorporated. (1999). Montaj MAGMAP filtering; 2–D frequency domain of potential field data extension for Oasis Montaj v. 6.1.
 .. [Grombein2013] Grombein, T., Seitz, K., Heck, B. (2013), Optimized formulas for the gravitational field of a tesseroid, Journal of Geodesy. doi:`10.1007/s00190-013-0636-1 <https://doi.org/10.1007/s00190-013-0636-1>`__
 .. [Hofmann-WellenhofMoritz2006] Hofmann-Wellenhof, B., & Moritz, H. (2006). Physical Geodesy (2nd, corr. ed. 2006 edition ed.). Wien ; New York: Springer.
 .. [LiGotze2001] Li, X. and H. J. Gotze, 2001, Tutorial: Ellipsoid, geoid, gravity, geodesy, and geophysics, Geophysics, 66(6), p. 1660-1668, doi:`10.1190/1.1487109 <https://doi.org/10.1190/1.1487109>`__
 .. [Nagy2000] Nagy, D., Papp, G. & Benedek, J.(2000). The gravitational potential and its derivatives for the prism. Journal of Geodesy 74: 552. doi:`10.1007/s001900000116 <https://doi.org/10.1007/s001900000116>`__
 .. [Nagy2002] Nagy, D., Papp, G. & Benedek, J.(2002). Corrections to "The gravitational potential and its derivatives for the prism". Journal of Geodesy. doi:`10.1007/s00190-002-0264-7 <https://doi.org/10.1007/s00190-002-0264-7>`__
 .. [Oliveira2021] Oliveira Jr, Vanderlei C. and Uieda, Leonardo and Barbosa, Valeria C. F.. Sketch of three coordinate systems: Geocentric Cartesian, Geocentric Geodetic, and Topocentric Cartesian. figshare. doi: `10.6084/m9.figshare.15044241.v1 <https://doi.org/10.6084/m9.figshare.15044241.v1>`__
+.. [Salem2014] Salem, A., Green, C., Cheyney, S., Fairhead, J. D., Aboud, E., & Campbell, S. (2014). Mapping the depth to magnetic basement using inversion of pseudogravity: Application to the Bishop model and the Stord Basin, northern North Sea. Interpretation, 2(2), T69-T78. doi: `10.1190/INT-2013-0105.1 <https://doi.org/10.1190/INT-2013-0105.1>`__
 .. [Soler2019] Soler, S. R., Pesce, A., Gimenez, M. E., & Uieda, L. (2019). Gravitational field calculation in spherical coordinates using variable densities in depth, Geophysical Journal International. doi: `10.1093/gji/ggz277 <https://doi.org/10.1093/gji/ggz277>`__
 .. [Soler2021] Soler, S. R. and Uieda, L. (2021). Gradient-boosted equivalent sources, Geophysical Journal International. doi:`10.1093/gji/ggab297 <https://doi.org/10.1093/gji/ggab297>`__
 .. [Uieda2015] Uieda, Leonardo (2015). A tesserioid (spherical prism) in a geocentric coordinate system with a local-North-oriented coordinate system. figshare. Figure. doi: `10.6084/m9.figshare.1495525.v1 <https://doi.org/10.6084/m9.figshare.1495525.v1>`_

harmonica/__init__.py

@@ -20,7 +20,15 @@
 from .forward.tesseroid_layer import DatasetAccessorTesseroidLayer, tesseroid_layer
 from .gravity_corrections import bouguer_correction
 from .isostasy import isostasy_airy, isostatic_moho_airy
-from .transformations import derivative_upward
+from .transformations import (
+    derivative_easting,
+    derivative_northing,
+    derivative_upward,
+    gaussian_highpass,
+    gaussian_lowpass,
+    reduction_to_pole,
+    upward_continuation,
+)
 
 
 def test(doctest=True, verbose=True, coverage=False, figures=False):

harmonica/filters/__init__.py

@@ -7,4 +7,12 @@
 """
 Frequency domain filters meant to be applied on regular grids
 """
-from ._filters import derivative_upward_kernel
+from ._filters import (
+    derivative_easting_kernel,
+    derivative_northing_kernel,
+    derivative_upward_kernel,
+    gaussian_highpass_kernel,
+    gaussian_lowpass_kernel,
+    reduction_to_pole_kernel,
+    upward_continuation_kernel,
+)