Table 1 Details on the parameterization of the individual model parts. Here, the number of basic parameters refers to the number of parameters irrespective of an explicit time-dependence
Description of the model parameters | Number of basic parameters | Temporal parameterization | Number of parameters | |
|---|---|---|---|---|
Internal field | Time-dependent (\(n \le 15\)) | 255 | order-6 B-spline | 6375 |
Static (\(16 \le n \le 50\)) | 2345 | None | 2345 | |
External field | SM degree-1 | 3 | RC-index | 3 |
SM degree-2 | 5 | None | 5 | |
RC-baseline corrections | 3 | 80 bins (30 days) | 240 | |
GSM | 2 | None | 2 | |
Euler angles | CHAMP | 3 | 33 bins (30 days) | 99 |
Swarm-A | 3 | 50 bins (30 days) | 150 | |
Swarm-B | 3 | 50 bins (30 days) | 150 | |
Euler/Calibration | CryoSat-2 FGM1 | 12 | 91 bins (30 days) | 1092 |
CryoSat-2 FGM2 | 12 | 91 bins (30 days) | 1092 | |
CryoSat-2 FGM3 | 12 | 91 bins (30 days) | 1092 | |
GRACE-A | 12 | 120 bins (30 days) | 1440 | |
GRACE-B | 12 | 118 bins (30 days) | 1416 | |
Total number of parameters (no platform magnetometer data) | 9369 | |||
Total number of parameters | 15501 | |||