Magnetometer to expand understanding of Earth’s magnetic field

Gathering unprecedented detail about the Earth’s magnetic field, these high-precision and high-resolution measurements will improve scientists’ understanding of the Earth’s magnetic-field structure, evolution and interaction with the solar wind. The magnetic field, which shields the Earth from cosmic radiation and harmful charged particles in the solar wind, is weakening. Scientists hope the data also will shed light on why this is happening.

Lifted into their orbiting positions 450 and 530 kilometers above Earth by a Russian Rokot, the three identical satellites will be positioned so as to simultaneously acquire measurements in three different locations and time zones. Leti’s absolute scalar magnetometers will be deployed at the very tip of booms extending nine meters from the rear of each satellite platform, preventing interference by the crafts themselves.

Laurent Malier, CEO of Leti, commented: “The Swarm mission’s three absolute scalar magnetometers, which underscore Leti’s advanced sensor design-and-performance capabilities, provide the mission with critical technologies for understanding past, present and future dynamics of the magnetic field. This is a tribute to the technological excellence that characterizes Leti’s divisions and to our commitment to collaborate with French and European technology partners.”

The three measuring instruments that will directly contribute to the magnetic field studies are: a vector magnetometer to measure the components of the magnetic field in space; a stellar camera giving the orientation of the vector magnetometer in space; and a Leti-designed absolute scalar magnetometer for measuring the intensity of the field without drift or bias, i.e. without systematic error, and with unmatched precision and resolution. The ASM’s ability, unique in the world, to simultaneously measure the direction of the field will also be implemented in an experimental mode.

“We developed an architecture that is free of the orientation effects common to all standard scalar magnetometers based on magnetic resonance to take full advantage of the ASM’s performance. These instruments represent the latest and most effective technology available to measure key characteristics of the magnetic field,” comments Jean-Michel Léger, manager of Leti’s Space Applications Program.

Scientists will also use the magnetic field models resulting from the Swarm mission to further their understanding of atmospheric processes related to climate and weather. This will also help to improve the accuracy of navigation systems and will have practical applications in many different areas, such as space weather.