The SCM consists of a compact set of three search-coil antennas that are orthogonally mounted on a non-magnetic support, enabling the measurement of the three components of the fluctuating magnetic. A preamplifier sends the analog signal through the harness toward the platform where the electronic boxes are located that provide the power supply, the thermal control and perform the digitization and data processing. This preamplifier is located inside of the mechanical structure, the closest possible to the antennas.

The scientific requirements for Solar Orbiter mission are the measurement of the AC magnetic field between a few Hz and 10 kHz with intensities as low as 8 fT/ Hz around 2 kHz and a maximum intensity of 5 nT. The sensor includes one double-band antenna that covers the 10 kHz–500 kHz frequency range with a sensitivity of 50 fT/ Hz at 100 kHz. A block diagram of the SCM is shown in Figure 1.

The output voltage produced by one SCM antenna is passed to one of the three analyzers that filters and digitizes the analog signal with their own complex frequency response. The knowledge of the transfer function of the SCM antenna and the one of the analyzers allows to calibrate this voltage in magnetic field variations. Finally, SCM magnetic data are filtered with a high-pass filter above 3.5 Hz.

• The TNR receiver compute magnetic spectra from signal from the high frequency part (10 kHz–500 kHz) of the double band antenna.
• The TDS receiver produces high cadence waveforms of magnetic field variations from the high frequency part (10 kHz–500 kHz) of the double band antenna.
• The LFR receiver produces waveforms of magnetic field variations from the three antennas, at four sampling frequencies: 24576 Hz, 4096 Hz, 256 Hz and 16 Hz. LFR also produces low frequency spectral products including magnetic and electric fields.