Skip to main content

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