The Ørsted Satellite Project

Olsen, N. (1), R. Holme, G. Hulot, T. Sabaka, T. Neubert, L. Tøffner-Clausen, F. Primdahl, J. Jørgensen, J.-M. Leger, D. Barraclough, J. Bloxham, J. Cain, C. Constable, V. Golovkov, A. Jackson, P. Kotze, B. Langlais, S. Macmillan, M. Mandea, J. Merayo, L. Newitt, M. Purucker, T. Risbo, M. Stampe, A. Thomson, C. Voorhies

1. Danish Space Research Institute, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark. Fax.: +45 35 36 24 75. E-mail: nio@dsri.dk.

Abstract. 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 detailed models exist for only one previous epoch, 1980. Achieved rms misfit is 2~nT for the scalar intensity and 4~nT for the vector components perpendicular to the magnetic field. This model is of higher detail than the IGRF 2000, which for scientific purposes related to the Ørsted mission it supersedes.