The cosmic microwave background

To add in the CMB (either as something to observe, or a noise source), we add

sim = maria.Simulation(instrument=my_instrument,
                       site=my_site,
                       plan=my_plan,
                       atmosphere="2d",
                       cmb="generate")

This two-dimensional model is a simplified approximation of atmospheric turbulence (see T. W. Morris et al. (2022)) that lets us more efficiently simulate atmospheric fluctuations at higher resolutions. We can customize the CMB by specifying a set of cmb_kwargs to, e.g., increase the resolution of the generated map.

sim = maria.Simulation(instrument=my_instrument,
                       site=my_site,
                       plan=my_plan,
                       atmosphere="2d",
                       cmb="generate",
                       cmb_kwargs={"nside": 4096})