This gist holds the groundtrack plotter function

groundtrack.py

""" This script holds the function for plotting the groundtracks. """

# Poliastro modules
from poliastro.twobody import Orbit
from poliastro.bodies import Earth

# Astropy modules
from astropy import coordinates as coord
from astropy import units as u

# Plotting modules
import matplotlib.pyplot as plt
import cartopy.crs as ccrs

def groundtrack(ss):
    """ Plots the groundtrack of an Orbit.

    Parameters
    ----------
    ss: poliastro.twobody.orbit.Orbit
        Orbit for making the groundtrack
    """

    # Transform GCRS to ITRS
    ss_gcrs = ss.sample()
    ss_itrs = coord.GCRS(coord.CartesianRepresentation(ss_gcrs.x, ss_gcrs.y, ss_gcrs.z)).transform_to(coord.ITRS)

    # Convert both systems to lat and lon
    latlon_gcrs = ss_gcrs.represent_as(coord.SphericalRepresentation)
    latlon_itrs = ss_itrs.represent_as(coord.SphericalRepresentation)

    # Plotting the groundtrack
    fig, ax = plt.subplots()
    ax = plt.axes(projection=ccrs.PlateCarree())
    ax.stock_img()
    ax.plot(latlon_gcrs.lon.to(u.deg), latlon_gcrs.lat.to(u.deg), 'r', transform=ccrs.Geodetic(), label='GCRS');
    ax.plot(latlon_itrs.lon.to(u.deg), latlon_itrs.lat.to(u.deg), 'b', transform=ccrs.Geodetic(), label='ITRS');
    ax.legend(loc='upper center', shadow=True, fontsize='x-large')
    ax.plot()


if __name__ == '__main__':

    # Creating the orbit
    r = [-6045, -3490, 2500] * u.km
    v = [-3.457, 6.618, 2.533] * u.km / u.s
    ss = Orbit.from_vectors(Earth, r, v)
    groundtrack(ss)
    plt.show()