C. Finlay, S. Maus, C. Beggan, T. Bondar, A. Chambodut et al., International geomagnetic reference field: the eleventh generation, Geophys J Int, vol.183, issue.3, pp.1216-1230, 2010.
URL : https://hal.archives-ouvertes.fr/hal-00527822

A. Fournier, G. Hulot, D. Jault, W. Kuang, A. Tangborn et al., An Introduction to Data Assimilation and Predictability in Geomagnetism, Space Science Reviews, vol.65, issue.3, pp.247-291, 2010.
DOI : 10.1007/s11214-010-9669-4
URL : https://hal.archives-ouvertes.fr/insu-00565056

A. Fournier, J. Aubert, and E. Thébault, A candidate secular variation model for IGRF-12 based on Swarm data and inverse geodynamo modelling, Earth, Planets and Space, vol.94, issue.45, pp.81-91, 2015.
DOI : 10.1186/s40623-015-0245-8

E. Friis-christensen, H. Lühr, and G. Hulot, Swarm: A constellation to study the Earth???s magnetic field, Earth, Planets and Space, vol.388, issue.2, pp.351-358, 2006.
DOI : 10.1186/BF03351933

O. Gravrand, A. Khokhlov, L. Mouël, J. Léger, and J. , On the calibration of a vectorial 4He pumped magnetometer, Earth, Planets and Space, vol.6, issue.N10, pp.949-958, 2001.
DOI : 10.1186/BF03351692

R. Holme and J. Bloxham, The treatment of attitude errors in satellite geomagnetic data, Physics of the Earth and Planetary Interiors, vol.98, issue.3-4, pp.221-233, 1996.
DOI : 10.1016/S0031-9201(96)03189-5

G. Hulot, T. Sabaka, N. Olsen, and A. Fournier, The Present and Future Geomagnetic Field, Geomagnetism. Treatise on Geophysics, vol.5, 2015.
DOI : 10.1016/B978-0-444-53802-4.00096-8

G. Hulot, P. Vigneron, J. Léger, I. Fratter, N. Olsen et al., 's absolute magnetometer experimental vector mode, an innovative capability for space magnetometry, Geophysical Research Letters, vol.47, issue.15, pp.1352-1359, 1002.
DOI : 10.1002/2014GL062659
URL : http://orbit.dtu.dk/ws/files/105710738/Hulot_et_al_2015_Geophysical_Research_Letters.pdf

J. Léger, F. Bertrand, T. Jager, M. Prado, I. Fratter et al., Swarm Absolute Scalar and Vector Magnetometer Based on Helium 4 Optical Pumping, Procedia Chemistry, vol.1, issue.1, pp.634-637, 2009.
DOI : 10.1016/j.proche.2009.07.158

J. Léger, T. Jager, F. Bertrand, G. Hulot, L. Brocco et al., In-flight performance of the Absolute Scalar Magnetometer vector mode on board the Swarm satellites, Earth, Planets and Space, vol.1, issue.5, pp.57-67, 2015.
DOI : 10.1186/s40623-015-0231-1

F. Lowes, Mean-square values on sphere of spherical harmonic vector fields, Journal of Geophysical Research, vol.71, issue.8, p.2179, 1966.
DOI : 10.1029/JZ071i008p02179

S. Macmillan and C. Finlay, The International Geomagnetic Reference Field, Geomagnetic observations and models, pp.265-76, 2011.
DOI : 10.1007/978-90-481-9858-0_10
URL : https://hal.archives-ouvertes.fr/hal-00527822

P. Mauersberger, Das Mittel der Energiedichte des geomagnetischen Hauptfeldes an der Erdoberfläche und seine säkulare Änderung, Gerl Beitr Geophys, vol.65, pp.207-222, 1956.

N. Olsen, H. Lühr, C. Finlay, T. Sabaka, I. Michaelis et al., The CHAOS-4 geomagnetic field model, Geophysical Journal International, vol.197, issue.2, pp.815-842, 2014.
DOI : 10.1093/gji/ggu033
URL : http://gfzpublic.gfz-potsdam.de/pubman/item/escidoc:898905:3/component/escidoc:900891/898905.pdf

N. Olsen, G. Hulot, V. Lesur, C. Finlay, C. Beggan et al., The Swarm Initial Field Model for the 2014 geomagnetic field, Geophysical Research Letters, vol.25, issue.16, pp.1092-109810, 1002.
DOI : 10.1029/98GL02211
URL : https://hal.archives-ouvertes.fr/insu-01405271

A. Richmond, Ionospheric Electrodynamics Using Magnetic Apex Coordinates., Journal of geomagnetism and geoelectricity, vol.47, issue.2, pp.191-212, 1995.
DOI : 10.5636/jgg.47.191

E. Thébault, C. Finlay, C. Beggan, P. Alken, A. J. Barrois et al., International Geomagnetic Reference Field: the 12th generation, Earth, Planets and Space, vol.28, issue.6, p.79, 2015.
DOI : 10.1186/s40623-015-0228-9

E. Thébault, C. Finlay, P. Alken, C. Beggan, E. Canet et al., Evaluation of candidate geomagnetic field models for IGRF-12, Earth, Planets and Space, vol.67, issue.11, 2015.
DOI : 10.1186/s40623-015-0273-4