Propagating with Perturbations

Propagating an orbit with spherical harmonics and third body effects

import numpy as np
import pyvista as pv

import mirage as mr
import mirage.vis as mrv

Defining our initial condition and the propagation times

n = 1
rv0 = np.random.uniform(
    low=[7_000, 0, -1_000, 0, 2.5, 7],
    high=[8_000, 1_000, 0, 0.3, 2.8, 7.3],
    size=(n, 6),
)
dates, epsecs = mr.date_linspace(
    mr.now(), mr.now() + mr.days(50), 100_000, return_epsecs=True
)

Propagating with the full EGM96 gravity model and Sun/Moon third-body accelerations

mr.tic()
rv = mr.integrate_orbit_dynamics(
    rv0,
    dates,
    gravity_harmonics_degree=4,
    third_bodies=['sun', 'moon', 'jupiter'],
    int_tol=1e-9,  # Because I want this example to render quickly
)
rv = rv.reshape((dates.size, 6, -1))
mr.toc()

pl = pv.Plotter()
mrv.plot_earth(pl, date=dates[0])
for i in range(rv.shape[-1]):
    r = rv[:, :3, i]
    mrv.plot3(
        pl,
        r,
        lighting=True,
        scalars=epsecs,
        cmap='twilight',
        show_scalar_bar=False,
        line_width=15,
    )
pl.show()

Elapsed time: 1.53e+01 seconds