Table 1 Summary of parameters defining the model setup in CHAOS-7
From: The CHAOS-7 geomagnetic field model and observed changes in the South Atlantic Anomaly
Setup parameter | Description | |
|---|---|---|
\(N_\text {tdep}\) | Maximum SH degree of time-dependent internal field | 20 |
J | Order of B-splines | 6 |
\(\Delta t_k\) | B-spline knot spacing | 0.5 year |
\(t_\text {start}\) | Start time of spline basis | 1997.1 |
\(t_\text {end}\) | End time of spline basis | 2020.1 |
\(N_\text {int}\) | Maximum SH degree of static internal field | 70 |
\(N_\text {SM}\) | Maximum SH degree of SM external field | 2 |
\(\Delta T_\text {SM1}\) | Bin size for degree 1 SM offsets | 30 days |
\(N_\text {GSM}\) | Maximum SH degree of GSM external field | 2 (only \(m=0\) terms) |
\(\Delta T_\text {Euler}\) | Bin size for Euler angle determination | 10 days |
\(\Delta T_\text {CAL}\) | Bin size for calibration parameters | 21 days |