compute the Gauss coefficients of the MF, SV and SA of the internal field

To compute the Gauss coefficients of the Main Field (MF), Secular Variation (SV), and Secular Acceleration (SA) of the internal field, you can use the CHAOS model. Here is an example code snippet:

# Compute the Gauss coefficients
nmax = 13  # Maximum degree and order
time = np.linspace(1900, 2022, 123)  # Time array

# Compute MF coefficients
mf_coeffs = model.synth_coeffs_tdep(time, nmax=nmax, deriv=0)

# Compute SV coefficients
sv_coeffs = model.synth_coeffs_tdep(time, nmax=nmax, deriv=1)

# Compute SA coefficients
sa_coeffs = model.synth_coeffs_tdep(time, nmax=nmax, deriv=2)

# Print the computed coefficients
print("Main Field coefficients:")
print(mf_coeffs)
print("Secular Variation coefficients:")
print(sv_coeffs)
print("Secular Acceleration coefficients:")
print(sa_coeffs)

In this code, we first specify the maximum degree and order `nmax` for the Gauss coefficients. Then, we define a time array `time` over which we want to compute the coefficients.

We use the `synth_coeffs_tdep()` function to compute the Gauss coefficients for the Main Field (`deriv=0`), Secular Variation (`deriv=1`), and Secular Acceleration (`deriv=2`). The function takes the time array, maximum degree and order, and the derivative order as parameters.

Finally, we print the computed coefficients for each component.

Please note that you need to have the CHAOS model and its corresponding Python package installed in order to run this code successfully.