clean up the ray-tracer trough the ionosphere

(this description is extracted from a slack conversation)

general

the ray-tracer is here: https://gitlab.irf.se/danielk/sorts/-/blob/develop/src/sorts/errors/ionospheric_ray_trace.py?ref_type=heads

it is using the pyglow model to get the ionosphere parameter that can be used to get a "refractive index" for radio waves

stuff to improve:

• there are lots of 1 and 2 character variable names in there that should be described or more verbose
• it needs some comments
• it has hard-coded constants, code that could probably be separated out to functions
• the deviation of the k-vector (direction of propagation) due to ray-bending is not returned, (just the angle is returned)
• might run not at the moment