geocat.comp.gradient.rad_lat_wgs84#

geocat.comp.gradient.rad_lat_wgs84(lat)#

The radius calculation for the wgs84 ellipsoid at a latitude uses a taylor series from.

\[radius = \sqrt{a^2 \cdot cos(lat)^2+b^2 \cdot sin(lat)^2}\]

This returns the radius of the ellipsoid for a given latitude This is accurate to within floating point error.

note: This doesn’t need to be a taylor series, though the taylor series is faster and a needed step for the arc_lat_wgs84 function to avoid the elliptic integral

Parameters

lat (numpy.ndarray, xarray.DataArray) – 2-dimensional dataset, of orthographic latitude coordinates

Returns