Astrid-2 Satellit Magnetometer

In collaboration with the Swedish Rymdbolaget, Kungliga Tekniska Högskolan in Stockholm and with the Geophysical Observatory, Sodankylä in Finland has has the magnetometer group at the department of Automation been offered a payload launch on the Swedish satellite "Astrid 2" of the 2nd generation Ørsted satellite magnetometer. Prior to the satellite launch the magnetometer group was offered a payload launch on the NASA sounding rocket "Auroral Turbulence 2" in collaboration with Cornell University and University of New Hampshire.The magnetometer is based on a Digital Signal Processor controlling the feedback loop of the magnetometer. The sensor is excited with a highly symmetrical signal (only odd harmonics) at 8 kHz and the output of the sensor is digitized with an 12 bit A/D converter. The DSP calculates the even harmonics contents of the signal which is related to the external field on the sensor. By adjusting a current through a coil with an 18 bit D/A converter the DSP minimizes the even harmonic signal.Less than a year has passed from the first design meeting in Sodankylä to the integration of the three space qualified magnetometers on the sounding rocket and the magnetic calibration at NASA Wallops Flight Facility in December 1996.