MAGIC
MAGIC L2 Data Products
MAGIC Level 2 data products consist of 3-axis magnetic field measurements sampled at 128 samples per second in the Region of Interest (ROI) and 16 samples per second during back orbit operation. The CDFs of these data provide MAGIC as measured in its own instrument frame, de-spun into the GEI2000 reference coordinate system, and the North-East-Center (NEC) coordinate system.
Note: Data gaps are present in the current Level 2 magnetic fields data pertaining to lack of definitive spacecraft attitude needed to produce reliably de-spun data. MAGIC Level 2 CDFs will update as more definitive spacecraft attitude data is provided.
Calibration: Level 2 data products regress the original sensor data against the scalar magnitude of a reference field, IGRF, using least squares techniques. This regression, at a minimum, provides a 9 factor (sensitivity, orthogonality correction, and offsets) of the three magnetometer axes, which provides a basis for rotating into other desired coordinate systems. We use extended scalar-vector formulae to correct for per-axis non-linear response, cross-axis sensor feedback, and temperature dependence of the sensor response. Data used for the scalar-vector calibrations are sampled during eclipsed periods, which avoids stray signals from the solar cells. Alongside the three coordinate systems provided as described above, a data quality flag is also provided. Time periods marked as a ‘1’ have been contaminated by the satellite magneto-torquers with no attempt to remove these signals in the data, ‘2’ indicates there is no definitive kernel attitude for this time range, and ‘3’ is a combination of no definitive attitude and magneto-torquer operations. All other data should be marked as ‘0’ but the data quality flags may extend to other values as the mission progresses.