def get_positions(times, pass_obj):
spacecraft = twoline2rv(pass_obj['TLE'][0], pass_obj['TLE'][1], wgs84)
telescope_ecef = AF.lla_to_ecef(LAT, LON, ALT, geodetic=True)
utc0 = pass_obj['EPOCH']
telescope_ecis = []
spacecraft_ecis = []
sun_ecis = []
for time in times:
now = utc0 + datetime.timedelta(seconds=time)
sun_vec = AF.vect_earth_to_sun(now)
sc_eci, _ = spacecraft.propagate(now.year, now.month, now.day,
now.hour, now.minute, now.second)
sc_eci = asarray(sc_eci)
lst = AF.local_sidereal_time(now, LON)
telescope_eci = AF.Cz(lst) @ telescope_ecef
obs_vec = telescope_eci - sc_eci
telescope_ecis.append(telescope_eci)
spacecraft_ecis.append(sc_eci)
sun_ecis.append(sun_vec)
return vstack(spacecraft_ecis), vstack(telescope_ecis), vstack(sun_ecis)
def states_to_lightcurve(times, states, pass_obj, quats=False):
lightcurve = []
spacecraft = twoline2rv(pass_obj['TLE'][0], pass_obj['TLE'][1], wgs84)
telescope_ecef = AF.lla_to_ecef(LAT, LON, ALT, geodetic=True)
utc0 = pass_obj['EPOCH']
for time, state in zip(times, states):
now = utc0 + datetime.timedelta(seconds=time)
sun_vec = AF.vect_earth_to_sun(now)
sc_eci, _ = spacecraft.propagate(now.year, now.month, now.day,
now.hour, now.minute, now.second)
sc_eci = asarray(sc_eci)
# if AF.shadow(sc_eci,sun_vec):
# #if the spacecraft is in shadow its brightness is zero
# print("IN SHADOW")
# lightcurve.append(0)
# continue
lst = AF.local_sidereal_time(now, LON)
telescope_eci = AF.Cz(lst) @ telescope_ecef
obs_vec = telescope_eci - sc_eci
if quats:
eta = state[0]
eps = state[1:4]
dcm_body2eci = R.from_quat(hstack([eps, eta])).as_dcm().T
else:
eulers = state[:3]
dcm_body2eci = R.from_euler(ROTATION, eulers).as_dcm().T
power = 0
for facet, area in zip(FACETS, AREAS):
normal = dcm_body2eci @ facet
if dot(normal, sun_vec) > 0 and dot(normal, obs_vec) > 0:
power += phong_brdf(obs_vec, sun_vec, normal, area)
lightcurve.append(power)
lightcurve = hstack(lightcurve)
return lightcurve
def measurement_function(state, time):
print(state)
eulers = state[:3]
dcm_body2eci = R.from_euler(ROTATION, eulers).as_dcm().T
power = 0
now = UTC0 + datetime.timedelta(seconds=time)
sc_eci, _ = SPACECRAFT.propagate(now.year, now.month, now.day, now.hour,
now.minute, now.second)
sc_eci = asarray(sc_eci)
lst = AF.local_sidereal_time(now, LON)
telescope_eci = AF.Cz(lst) @ TELESCOPE_ECEF
obs_vec = telescope_eci - sc_eci
sun_vec = AF.vect_earth_to_sun(now)
for facet, area in zip(FACETS, AREAS):
normal = dcm_body2eci @ facet
power += phong_brdf(OBS_VEC, SUN_VEC, normal, area)
return array([power])
def main():
angular_velocity0 = array([0, 0.1, 0])
# eta0 = 1
# eps0 = array([0,0,0])
q0 = R.random(random_state=1111).as_quat()
eta0 = q0[3]
eps0 = q0[0:3]
eulers = array([0, 0, 0])
state0 = hstack([eta0, eps0, angular_velocity0])
solver = ode(propagate_quats)
solver.set_integrator('lsoda')
solver.set_initial_value(state0, 0)
solver.set_f_params(INERTIA, False)
newstate = []
time = []
tspan = PASS['TIME'][-1]
while solver.successful() and solver.t < tspan:
newstate.append(solver.y)
time.append(solver.t)
solver.integrate(solver.t + DT)
newstate = vstack(newstate)
time = hstack(time)
#Generate lightcurve
lightcurve = states_to_lightcurve(time, newstate, PASS, quats=True)
#lightcurve += random.normal(0, MEASUREMENT_VARIANCE, size = lightcurve.shape)
#Save Data
save('true_lightcurve', lightcurve)
save('true_states', newstate)
save('time', time)
sc_pos, tel_pos, sun_pos = get_positions(time, PASS)
save('sc_pos', sc_pos)
save('tel_pos', tel_pos)
save('sun_pos', sun_pos)
colors = []
for x, y in zip(sc_pos, sun_pos):
if AF.shadow(x, y) == 0:
colors.append('k')
else:
colors.append('b')
fig = plt.figure()
ax = Axes3D(fig)
AP.plot_earth(ax)
ax.scatter(sc_pos[:, 0], sc_pos[:, 1], sc_pos[:, 2], c=colors)
AP.plot_orbit(ax, tel_pos)
AP.scale_plot(ax)
azimuth, elevation = AF.pass_az_el(tel_pos, sc_pos)
fig = plt.figure()
ax = fig.add_subplot(111, projection='polar')
#matplotlib takes azimuth in radians and elevation in degrees for some reason :/
ax.scatter(radians(azimuth), 90 - elevation, c=colors)
ax.set_ylim([0, 90])
plt.figure()
plt.plot(time, lightcurve)
plt.show()
AREAS = ESTIMATE.AREAS
OBS_VEC = ESTIMATE.OBS_VEC
SUN_VEC = ESTIMATE.SUN_VEC
INERTIA = ESTIMATE.INERTIA
MEASUREMENT_VARIANCE = ESTIMATE.MEASUREMENT_VARIANCE
ROTATION = VARIABLES.ROTATION
DT = VARIABLES.DT
LAT = VARIABLES.LATITUDE
LON = VARIABLES.LONGITUDE
ALT = VARIABLES.ALTITUDE
PASS = VARIABLES.PASS
SPACECRAFT = twoline2rv(PASS['TLE'][0], PASS['TLE'][1], wgs84)
UTC0 = PASS['EPOCH']
TELESCOPE_ECEF = AF.lla_to_ecef(LAT, LON, ALT, geodetic=True)
def main():
case = 0
for indx, arg in enumerate(sys.argv):
if arg == '--2inertia':
case = 1
print('Including Inertia into state')
elif arg == '--fullinertia':
case = 2
elif arg == '--inertialoffset':
case = 3
print('Estimating inertial offset')
elif arg == '--constomega':
Noise_STD = Simulation_Configuration['Sensor STD']
Directory = Simulation_Configuration['Directory']
Exposure_Time = Simulation_Configuration['Exposure Time']
Real_Data = Simulation_Configuration['Real Data']
date = Satellite.epoch - datetime.timedelta(hours=1)
if not os.path.exists(Directory):
os.makedirs(Directory)
pass_list = []
mid_pass_flag = False
max_el = 0
while len(pass_list) < num_passes:
date += datetime.timedelta(seconds=1)
lst = AF.local_sidereal_time(date, Lon)
site = AF.observation_site(Lat, lst, Alt)
sc_pos, sc_vel = Satellite.propagate(*date.timetuple()[0:6])
sc_pos = asarray(sc_pos)
range_vec = sc_pos - site
sun_vec = AF.vect_earth_to_sun(date)
illuminated = AF.shadow(sc_pos, sun_vec)
above_horizon = dot(range_vec, site) > 0
SPA_less_than_90 = dot(sun_vec, site - sc_pos) > 0
if above_horizon and illuminated and SPA_less_than_90:
if mid_pass_flag == False:
print('Pass encountered', date)
mid_pass_flag = True
current_pass = {'Date0': date}
positions = []
for t in times:
date_t = date0 + datetime.timedelta(seconds=t)
solver.set_initial_value(state0, 0)
solver.integrate(t)
positions.append(solver.y)
obs_vecs = []
sun_vecs = []
sat_poss = []
site_poss = []
range_vecs = []
for t, state in zip(times, positions):
date = date0 + datetime.timedelta(seconds=t)
lst = AF.local_sidereal_time(date, LON)
site = AF.observation_site(LAT, lst, ALT)
#telescope_ecef = AF.lla_to_ecef(LAT, LON, ALT, geodetic = True)
#site = AF.Cz(lst)@telescope_ecef
sc_pos, sc_vel = Satellite.propagate(*date.timetuple()[0:6])
sc_pos = state[0:3]
sc_pos = asarray(sc_pos)
range_vec = sc_pos - site
sun_vec = AF.vect_earth_to_sun(date)
obs_vecs.append(site - sc_pos)
sun_vecs.append(sun_vec)
sat_poss.append(sc_pos)
site_poss.append(site)
range_vecs.append(range_vec)
positions = []
for t in times:
date_t = date0 + datetime.timedelta(seconds = t)
sc_pos, _ = Satellite.propagate(*date_t.timetuple()[0:6])
positions.append(sc_pos)
obs_vecs = []
sun_vecs = []
sat_poss = []
site_poss = []
range_vecs = []
for t, state in zip(times, positions):
date = date0 + datetime.timedelta(seconds = t)
lst = AF.local_sidereal_time(date, LON)
#site = AF.observation_site(LAT, lst, ALT)
sc_pos, sc_vel = Satellite.propagate(*date.timetuple()[0:6])
#sc_pos = state[0:3]
sc_pos = asarray(sc_pos)
range_vec = sc_pos - site
sun_vec = AF.vect_earth_to_sun(date)
telescope_ecef = AF.lla_to_ecef(LAT, LON, ALT, geodetic = True)
site = AF.Cz(lst)@telescope_ecef
obs_vecs.append(site - sc_pos)
sun_vecs.append(sun_vec)
sat_poss.append(sc_pos)
site_poss.append(site)
range_vecs.append(range_vec)