Aligned and Constrained

Simulates and animates an aligned and constrained attitude profile

Note

If you want to record a .mp4 video instead, try pl.open_movie("aligned_and_constrained.mov", framerate=30, quality=9)

/Users/liamrobinson/Documents/maintained-research/mirage/mirage/orbit.py:504: UserWarning: Velocity is transformation is missing omega cross r term from TEME to J2000, but this is tiny
  warnings.warn(

import numpy as np
import pyvista as pv

import mirage as mr
import mirage.vis as mrv

data_points = 100
obj = mr.SpaceObject('matlib_gps_iii.obj', identifier='NAVSTAR 80 (USA 309)')
jd0, jdf = 2459840.6618391783, 2459840.9182615164
date0, datef = mr.jd_to_date(jd0), mr.jd_to_date(jdf)
(date_space, epsec_space) = mr.date_linspace(
    date0, datef, data_points, return_epsecs=True
)
(r, v) = obj.propagate(date_space, return_velocity=True)

orbit_normal = mr.hat(np.cross(r, v))
sat_nadir = -mr.hat(r)
t = epsec_space / np.max(epsec_space) * 4 * np.pi

sat_sun = mr.hat(mr.sun(date_space))
att = mr.AlignedAndConstrainedAttitude(
    sat_nadir, sat_sun, date_space, axis_order=(2, 0, 1)
)
c = att.dcms_at_dates(date_space)
quat = mr.dcm_to_quat(c)
(v1, v2, v3) = att.basis_vectors_at_dates(date_space)

sun_in_body = mr.stack_mat_mult_vec(c, sat_sun)
obs_in_body = mr.stack_mat_mult_vec(c, sat_nadir)

pl = pv.Plotter()
pl.open_gif('aligned_and_constrained.gif', fps=20)

mrv.plot3(pl, r, color='cyan', line_width=10)

omesh = obj._mesh.copy()
cdist = 300
pdist = cdist / 4
psize = 30
pl._on_first_render_request()
pl.render()
cam_light = pv.Light(
    color='white', attenuation_values=(0.0, 0.01, 0.0), positional=True
)

for i in range(data_points - 1):
    pl.camera.position = (
        r[i, :] - cdist * sat_nadir[i, :] + cdist / 10 * orbit_normal[i, :]
    )
    pl.camera.focal_point = r[i, :]
    mrv.render_spaceobject(
        pl, obj, origin=r[i, :], scale=5, opacity=1.0, quat=quat[i, :], lighting=True
    )
    mrv.plot_arrow(pl, r[i, :], v1[i, :], scale=pdist, name='arr_v1')
    mrv.plot_arrow(pl, r[i, :], v2[i, :], scale=pdist, name='arr_v2')
    mrv.plot_arrow(pl, r[i, :], v3[i, :], scale=pdist, name='arr_v3')
    mrv.plot_arrow(
        pl,
        r[i, :],
        sat_sun[i, :],
        scale=pdist,
        name='arr_sun',
        color='y',
        label='Sun',
    )
    mrv.plot_earth(pl, date=date_space[i])
    cam_light.position = pl.camera.position
    cam_light.focal_point = pl.camera.focal_point
    if i == 0:
        pl.add_light(cam_light)

    pl.write_frame()
    obj._mesh.copy_from(omesh)
pl.close()