Ørsted Initial Field Model

Magnetic measurements taken by the Ørsted satellite during geomagnetic quiet conditions around January 1, 2000 have been used to derive a spherical harmonic model of the Earth's magnetic field for epoch 2000.0. The maximum degree and order of the model is 19 for internal, and 2 for external, source fields; however, coefficients above degree 14 may not be robust. Such a detailed model exists for only one previous epoch, 1980. Achieved rms misfit is <2 nT for the scalar intensity and <3 nT for one of the vector components perpendicular to the magnetic field. For scientific purposes related to the Ørsted mission, this model supercedes IGRF 2000.