March 7, 2017



Ørsted is a Danish project (DMI) in international partnership with NASA and CNES for the science part.

The science objectives of Ørsted are:

  • to study the generation of magnetic fields in the fluid core and the magnetic and electrical properties of the solid Earth
  • to study the Earth's magnetic field as the controlling parameter of the magnetosphere, its interaction with the solar wind, and all the physical processes that take place in the Earth's plasma environment, including phenomena like aurora and magnetic storms

To fulfil these science objectives, the payload consists of the following subsystems:

  • a Compact Spherical Coil (CSC) three-axis magnetometer for measuring magnetic field vectors
  • an Overhauser proton-precession magnetometer (OVH) for measuring magnetic field amplitude
  • a Star Imager (SIM) to determine the attitude of the CSC magnetometer
  • a six solid-state Charged Particles Detectors (CPD) to measure energetic particle radiation in the upper polar atmosphere
  • a Turbo Rogue GPS receiver for atmospheric profiling

Considering the long-term involvement of the French scientific community in studying Earth's internal and external magnetic fields, CNES provided the Overhauser magnetometer (OVH) developped by the LETI electronics, technology and instrumentation laboratory at CEA.

Ørsted was launched on the 23 february 1999, from Vandenberg Air force Base (VAFB), California.
The satellite is still flying and acquiring measurements of Earth's magnetic field.

Ørsted science results are detailed on the DMI website.

Amplitudes of the magnetic field (upper map) and its variations (lower map) in 20 years.
In the South Atlantic the variations are over 10%. ©IPGP