pysecs.T_cf#
- pysecs.T_cf(obs_loc: ndarray, sec_loc: ndarray) ndarray#
Calculate the curl free magnetic field transfer function.
The transfer function goes from SEC location to observation location and assumes unit current SECs at the given locations.
The curl-free SEC, together with its associated radial field-aligned currents (FACs), produces no magnetic field at or below its current shell (Fukushima’s theorem generalized to a sphere) and a purely azimuthal magnetic field above it. A positive scaling factor corresponds to a FAC flowing into the ionosphere at the SEC pole, horizontal sheet currents directed away from the pole, and uniformly distributed FACs flowing out of the ionosphere elsewhere.