def calc_perigee_map(start='2010:114:20:00:00', stop='2010:117:16:00:00', ngrid=50):
# Get orbital ephemeris in requested time range
print ('Fetching ephemeris')
objs = ('orbit', 'lunar', 'solar')
axes = ('x', 'y', 'z')
msids = ['{0}ephem0_{1}'.format(obj, axis)
for obj in objs
for axis in axes]
ephems = fetch.MSIDset(msids, start, stop)
times = ephems[msids[0]].times.copy()
n_ephem = len(ephems[msids[0]].vals)
if any(len(ephems[msid].vals) != n_ephem for msid in msids):
raise ValueError('Unexpected mismatch in ephemeris telemetry sampling')
ephem_xyzs = {}
for obj in ('orbit', 'lunar', 'solar'):
msids = ('{0}ephem0_{1}'.format(obj, axis) for axis in axes)
ephem_xyzs[obj] = np.array([ephems[msid].vals for msid in msids])
illum_maps = []
illum_idxs = []
antisun, xs, ys = get_antisun_grid(ngrid)
antisun_pitches, phis = antisun.img2polar(xs, ys)
for i_ephem, ephem_xyz in enumerate(ephem_xyzs['orbit'].transpose()):
# Calculate a grid of attitude vectors centered on the anti-sun line and extending
# from sun-pitch=180 (center) to sun-pitch=45 (edge).
orbit_r = np.sqrt(np.sum(ephem_xyzs['orbit'][:, i_ephem]**2))
if orbit_r > 50000e3:
continue
sun_eci = ephem_xyzs['solar'][:, i_ephem] - ephem_xyzs['orbit'][:, i_ephem]
att_vecs = antisun.img2eci(xs, ys, sun_eci)
ras, decs = Ska.quatutil.eci2radec(att_vecs)
illum_map = np.zeros((ngrid, ngrid), dtype=np.float32)
print i_ephem, n_ephem, ephem_xyz
for iy in range(ngrid):
for ix in range(ngrid):
i_vec = iy * ngrid + ix
if antisun_pitches[i_vec] < 135:
ra, dec = ras[i_vec], decs[i_vec]
roll = Ska.Sun.nominal_roll(ra, dec, times[i_ephem])
_, att_illums, _ = taco2.calc_earth_vis(ephem_xyz, [ra, dec, roll], max_reflect=5)
illum = sum(att_illums)
else:
illum = 0.0
illum_map[iy, ix] = illum
illum_idxs.append(i_ephem)
illum_maps.append(illum_map)
# debug_here()
return dict(illums=np.array(illum_maps),
illum_idxs=np.array(illum_idxs),
times=times,
antisun=antisun,
ephem_xyzs=ephem_xyzs,
)
def calc_illums(queue, chandra_ecis, att):
"""Calculate the illumination (Earth solid angle) at specified ephemeris
points ``chandra_ecis`` and attitude ``att``. Put the result into the
multiprocess ``queue``.
"""
illums = []
for chandra_eci in chandra_ecis:
vis, illum, rays = taco2.calc_earth_vis(chandra_eci, att, max_reflect=5)
illums.append(sum(illum))
queue.put(illums)
def calc_vis_values(queue, iproc, times, chandra_ecis, q1s, q2s, q3s, q4s):
outvals = []
for t, chandra_eci, q1, q2, q3, q4 in zip(times, chandra_ecis, q1s, q2s, q3s, q4s):
alt = np.sqrt(np.sum(chandra_eci**2))/1e3
date = re.sub(r'\.000$', '', DateTime(t).date)
q_att = Quaternion.normalize([q1,q2,q3,q4])
vis, illum, rays = taco.calc_earth_vis(chandra_eci, q_att)
title = '%s alt=%6.0f illum=%s' % (date, alt, illum)
outvals.append((t, illum[0], sum(illum[1:]), alt, q1, q2, q3, q4))
if opt.verbose:
print title, taco.norm(chandra_eci), q1, q2, q3, q4
elif iproc == 0:
print 'Progress: %d%%\r' % int((100. * len(outvals)) / len(times) + 0.5),
sys.stdout.flush()
if opt.movie:
plot_vis_image(title, date, rays, vis, iproc)
queue.put(outvals)
def calc_vis_values(queue, iproc, times, chandra_ecis, q1s, q2s, q3s, q4s):
outvals = []
for t, chandra_eci, q1, q2, q3, q4 in zip(times, chandra_ecis, q1s, q2s,
q3s, q4s):
alt = np.sqrt(np.sum(chandra_eci**2)) / 1e3
date = re.sub(r'\.000$', '', DateTime(t).date)
q_att = Quaternion.normalize([q1, q2, q3, q4])
vis, illum, rays = taco.calc_earth_vis(chandra_eci, q_att)
title = '%s alt=%6.0f illum=%s' % (date, alt, illum)
outvals.append((t, illum[0], sum(illum[1:]), alt, q1, q2, q3, q4))
if opt.verbose:
print title, taco.norm(chandra_eci), q1, q2, q3, q4
elif iproc == 0:
print 'Progress: %d%%\r' % int((100. * len(outvals)) / len(times) +
0.5),
sys.stdout.flush()
if opt.movie:
plot_vis_image(title, date, rays, vis, iproc)
queue.put(outvals)
orbit_xyz = numpy.array([0., 0., -1000000e3])
p_earth_body = numpy.array([-11913349.37481491, 1600513.79810546, 6787847.04879577])
orbit_xyz = -p_earth_body
illums = []
illums2 = []
pitchs = numpy.linspace(0, 90.0, 45)
esa_directs = []
esa_refls = []
for pitch in pitchs:
print pitch
att = [0, pitch, 0]
vis, illum, rays = taco.calc_earth_vis(orbit_xyz, att, n_radiator_x=3, n_radiator_y=4, ngrid=100, max_reflect=6)
vis2, illum2, rays2 = taco2.calc_earth_vis(orbit_xyz, att, max_reflect=6)
illums.append(illum)
illums2.append(illum2)
direct, refl, total = Chandra.acis_esa.earth_solid_angle(Quat(att), orbit_xyz)
esa_directs.append(direct)
esa_refls.append(refl)
clf()
plot(pitchs, [x[0] for x in illums] , '-b', label='tla direct')
plot(pitchs, [x[0] for x in illums2] , '--b', label='tla direct-2', linewidth=4)
plot(pitchs, [x[1] for x in illums] , '-r', label='tla refl1')
plot(pitchs, [x[1] for x in illums2] , '--r', label='tla refl1-2', linewidth=4)
plot(pitchs, [x[2] for x in illums] , '-g', label='tla refl2')
# Loop over position of Chandra relative to Earth
iplot = 1
for orbit_xyz in numpy.array([
[11913349, -1600513, -6787847], # Test case 1
[0., 0., -1000000e3], # Earth along +Z and far away
[0., 0., -7000e3]
]): # Earth along +Z and near
print "Chandra position =", orbit_xyz
print "RA, Dec, Roll, total, direct, reflected"
directs = []
reflects = []
totals = []
for pitch in pitchs:
att = [0, pitch, 0] # RA, Dec, Roll. "Dec" set to pitch
vis, illum, rays = taco2.calc_earth_vis(orbit_xyz, att, max_reflect=10)
direct = illum[0]
reflect = sum(illum[1:])
total = sum(illum)
directs.append(direct)
reflects.append(reflect)
totals.append(total)
print "%5.1f %5.1f %5.1f %8.4e %8.4e %8.4e" % (att[0], att[1], att[2],
total, direct, reflect)
plt.subplot(3, 1, iplot)
plt.plot(pitchs, totals, '-k', label='Total')
plt.plot(pitchs, directs, '-b', label='Direct')
plt.plot(pitchs, reflects, '-r', label='Reflected')
plt.grid()
if iplot == 2:
plt.clf()
pitchs = numpy.linspace(0, 90.0, 46)
# Loop over position of Chandra relative to Earth
iplot = 1
for orbit_xyz in numpy.array([[11913349, -1600513, -6787847], # Test case 1
[0., 0., -1000000e3], # Earth along +Z and far away
[0., 0., -7000e3]]): # Earth along +Z and near
print "Chandra position =", orbit_xyz
print "RA, Dec, Roll, total, direct, reflected"
directs = []
reflects = []
totals = []
for pitch in pitchs:
att = [0, pitch, 0] # RA, Dec, Roll. "Dec" set to pitch
vis, illum, rays = taco2.calc_earth_vis(orbit_xyz, att, max_reflect=10)
direct = illum[0]
reflect = sum(illum[1:])
total = sum(illum)
directs.append(direct)
reflects.append(reflect)
totals.append(total)
print "%5.1f %5.1f %5.1f %8.4e %8.4e %8.4e" % (
att[0], att[1], att[2], total, direct, reflect)
plt.subplot(3, 1, iplot)
plt.plot(pitchs, totals , '-k', label='Total' )
plt.plot(pitchs, directs, '-b', label='Direct' )
plt.plot(pitchs, reflects, '-r', label='Reflected' )
plt.grid()
if iplot == 2: