Calculate ionospheric equivalent currents (1D)

Please use the new versions:
1D equivalent currents
2D equivalent currents

From ground magnetometer data the ionospheric equivalent currents can be calculated. These are currents that flow only within the ionospheric plane (assumed at 100 km altitude) and cause the same magnetic field on the ground as the actual ionospheric current system (which may be three-dimensional). So please note: Ionospheric equivalent currents are not necessarily equal to the actual currents!