def test_simulation_pointings_mjd(tmp_path):
sim = lbs.Simulation(
base_path=tmp_path / "simulation_dir",
start_time=Time("2020-01-01T00:00:00"),
duration_s=130.0,
)
fakedet = create_fake_detector()
sim.create_observations(detectors=[fakedet],
num_of_obs_per_detector=2,
split_list_over_processes=False)
sstr = lbs.SpinningScanningStrategy(spin_sun_angle_rad=10.0,
precession_rate_hz=10.0,
spin_rate_hz=0.1)
sim.generate_spin2ecl_quaternions(scanning_strategy=sstr,
delta_time_s=60.0)
instr = lbs.InstrumentInfo(spin_boresight_angle_rad=np.deg2rad(20.0))
for idx, obs in enumerate(sim.observations):
pointings_and_polangle = lbs.get_pointings(
obs,
spin2ecliptic_quats=sim.spin2ecliptic_quats,
detector_quats=np.array([[0.0, 0.0, 0.0, 1.0]]),
bore2spin_quat=instr.bore2spin_quat,
)
filename = Path(
__file__).parent / f"reference_obs_pointings{idx:03d}.npy"
reference = np.load(filename, allow_pickle=False)
assert np.allclose(pointings_and_polangle, reference)
def test_simulation_pointings_polangle(tmp_path):
sim = lbs.Simulation(base_path=tmp_path / "simulation_dir",
start_time=0.0,
duration_s=61.0)
fakedet = create_fake_detector(sampling_rate_hz=50.0)
sim.create_observations(detectors=[fakedet],
num_of_obs_per_detector=1,
split_list_over_processes=False)
assert len(sim.observations) == 1
obs = sim.observations[0]
sstr = lbs.SpinningScanningStrategy(spin_sun_angle_rad=0.0,
precession_rate_hz=0.0,
spin_rate_hz=1.0 / 60)
sim.generate_spin2ecl_quaternions(scanning_strategy=sstr, delta_time_s=0.5)
instr = lbs.InstrumentInfo(spin_boresight_angle_rad=0.0)
pointings_and_polangle = lbs.get_pointings(
obs,
spin2ecliptic_quats=sim.spin2ecliptic_quats,
detector_quats=np.array([[0.0, 0.0, 0.0, 1.0]]),
bore2spin_quat=instr.bore2spin_quat,
)
polangle = pointings_and_polangle[..., 2]
# Check that the polarization angle scans every value between -π
# and +π
assert np.allclose(np.max(polangle), np.pi, atol=0.01)
assert np.allclose(np.min(polangle), -np.pi, atol=0.01)
# Simulate the generation of a report
sim.flush()
def test_make_bin_map_api_simulation(tmp_path):
# We should add a more meaningful observation:
# Currently this test just shows the interface
sim = lbs.Simulation(base_path=tmp_path / "tut04",
start_time=0.0,
duration_s=86400.0)
sim.generate_spin2ecl_quaternions(
scanning_strategy=lbs.SpinningScanningStrategy(
spin_sun_angle_rad=np.radians(30), # CORE-specific parameter
spin_rate_hz=0.5 / 60, # Ditto
# We use astropy to convert the period (4 days) in
# minutes, the unit expected for the precession period
precession_rate_hz=1 / (4 * u.day).to("s").value,
))
instr = lbs.InstrumentInfo(name="core",
spin_boresight_angle_rad=np.radians(65))
det = lbs.DetectorInfo(name="foo", sampling_rate_hz=10)
obss = sim.create_observations(detectors=[det])
pointings = lbs.get_pointings(
obss[0],
sim.spin2ecliptic_quats,
detector_quats=[det.quat],
bore2spin_quat=instr.bore2spin_quat,
)
nside = 64
obss[0].pixind = hp.ang2pix(nside, pointings[..., 0], pointings[..., 1])
obss[0].psi = pointings[..., 2]
mapping.make_bin_map(obss, nside)
def __write_complex_observation(tmp_path, use_mjd: bool):
start_time = AstroTime("2021-01-01") if use_mjd else 0
time_span_s = 60
sampling_hz = 10
sim = lbs.Simulation(
base_path=tmp_path,
start_time=start_time,
duration_s=time_span_s,
)
scanning = lbs.SpinningScanningStrategy(
spin_sun_angle_rad=0.785_398_163_397_448_3,
precession_rate_hz=8.664_850_513_998_931e-05,
spin_rate_hz=0.000_833_333_333_333_333_4,
start_time=start_time,
)
spin2ecliptic_quats = scanning.generate_spin2ecl_quaternions(
start_time, time_span_s, delta_time_s=1.0)
instr = lbs.InstrumentInfo(
boresight_rotangle_rad=0.0,
spin_boresight_angle_rad=0.872_664_625_997_164_8,
spin_rotangle_rad=3.141_592_653_589_793,
)
det = lbs.DetectorInfo(
name="Dummy detector",
sampling_rate_hz=sampling_hz,
bandcenter_ghz=100.0,
quat=[0.0, 0.0, 0.0, 1.0],
)
sim.create_observations(detectors=[det])
obs = sim.observations[0]
obs.tod = np.random.random(obs.tod.shape)
obs.pointings = lbs.scanning.get_pointings(
obs,
spin2ecliptic_quats=spin2ecliptic_quats,
detector_quats=[det.quat],
bore2spin_quat=instr.bore2spin_quat,
)
obs.local_flags = np.zeros(obs.tod.shape, dtype="uint16")
obs.local_flags[0, 12:15] = 1
obs.global_flags = np.zeros(obs.tod.shape[1], dtype="uint32")
obs.global_flags[12:15] = 15
return obs, det, lbs.write_observations(sim=sim, subdir_name="")
def test_simulation_two_detectors():
sim = lbs.Simulation(start_time=0.0, duration_s=86400.0)
# Two detectors, the second rotated by 45°
quaternions = [
np.array([0.0, 0.0, 0.0, 1.0]),
np.array([0.0, 0.0, 1.0, 1.0]) / np.sqrt(2),
]
fakedet1 = create_fake_detector(sampling_rate_hz=1 / 3600,
quat=quaternions[0])
fakedet2 = create_fake_detector(sampling_rate_hz=1 / 3600,
quat=quaternions[1])
sim.create_observations(
detectors=[fakedet1, fakedet2],
num_of_obs_per_detector=1,
split_list_over_processes=False,
)
assert len(sim.observations) == 1
obs = sim.observations[0]
# The spacecraft stands still in L2, with no spinning nor precession
sstr = lbs.SpinningScanningStrategy(spin_sun_angle_rad=0.0,
precession_rate_hz=0.0,
spin_rate_hz=0.0)
sim.generate_spin2ecl_quaternions(sstr, delta_time_s=60.0)
assert sim.spin2ecliptic_quats.quats.shape == (24 * 60 + 1, 4)
instr = lbs.InstrumentInfo(spin_boresight_angle_rad=0.0)
pointings_and_polangle = lbs.get_pointings(
obs,
spin2ecliptic_quats=sim.spin2ecliptic_quats,
detector_quats=quaternions,
bore2spin_quat=instr.bore2spin_quat,
)
assert pointings_and_polangle.shape == (2, 24, 3)
assert np.allclose(pointings_and_polangle[0, :, 0],
pointings_and_polangle[1, :, 0])
assert np.allclose(pointings_and_polangle[0, :, 1],
pointings_and_polangle[1, :, 1])
# The ψ angle should differ by 45°
assert np.allclose(
np.abs(pointings_and_polangle[0, :, 2] -
pointings_and_polangle[1, :, 2]),
np.pi / 2,
)
def test_instrument_creation():
instr = lbs.InstrumentInfo(
name="test",
boresight_rotangle_rad=np.deg2rad(10.0),
spin_boresight_angle_rad=np.deg2rad(15.0),
spin_rotangle_rad=np.deg2rad(20.0),
)
assert instr.name == "test"
assert np.allclose(instr.boresight_rotangle_rad, np.deg2rad(10.0))
assert np.allclose(instr.spin_boresight_angle_rad, np.deg2rad(15.0))
assert np.allclose(instr.spin_rotangle_rad, np.deg2rad(20.0))
assert np.allclose(
instr.bore2spin_quat, np.array([-0.01137611, 0.1300295, 0.25660481, 0.9576622])
)
def test_simulation_pointings_still():
sim = lbs.Simulation(start_time=0.0, duration_s=86400.0)
fakedet = create_fake_detector(sampling_rate_hz=1 / 3600)
sim.create_observations(detectors=[fakedet],
num_of_obs_per_detector=1,
split_list_over_processes=False)
assert len(sim.observations) == 1
obs = sim.observations[0]
# The spacecraft stands still in L2, with no spinning nor precession
sstr = lbs.SpinningScanningStrategy(spin_sun_angle_rad=0.0,
precession_rate_hz=0.0,
spin_rate_hz=0.0)
sim.generate_spin2ecl_quaternions(sstr, delta_time_s=60.0)
assert sim.spin2ecliptic_quats.quats.shape == (24 * 60 + 1, 4)
instr = lbs.InstrumentInfo(spin_boresight_angle_rad=0.0)
# Move the Z vector manually using the last quaternion and check
# that it's rotated by 1/365.25 of a complete circle
boresight = np.empty(3)
lbs.rotate_z_vector(boresight, *sim.spin2ecliptic_quats.quats[-1, :])
assert np.allclose(np.arctan2(boresight[1], boresight[0]),
2 * np.pi / 365.25)
# Now redo the calculation using get_pointings
pointings_and_polangle = lbs.get_pointings(
obs,
spin2ecliptic_quats=sim.spin2ecliptic_quats,
detector_quats=np.array([[0.0, 0.0, 0.0, 1.0]]),
bore2spin_quat=instr.bore2spin_quat,
)
colatitude = pointings_and_polangle[..., 0]
longitude = pointings_and_polangle[..., 1]
polangle = pointings_and_polangle[..., 2]
assert np.allclose(colatitude, np.pi / 2), colatitude
assert np.allclose(np.abs(polangle), np.pi / 2), polangle
# The longitude should have changed by a fraction 23 hours /
# 365.25 days of a complete circle (we have 24 samples, from t = 0
# to t = 23 hr)
assert np.allclose(np.abs(longitude[..., -1] - longitude[..., 0]),
2 * np.pi * 23 / 365.25 / 24)
def test_scanning_quaternions(tmp_path):
sim = lbs.Simulation(base_path=tmp_path / "simulation_dir",
start_time=0.0,
duration_s=61.0)
fakedet = create_fake_detector(sampling_rate_hz=50.0)
sim.create_observations(detectors=[fakedet],
num_of_obs_per_detector=1,
split_list_over_processes=False)
assert len(sim.observations) == 1
obs = sim.observations[0]
sstr = lbs.SpinningScanningStrategy(spin_sun_angle_rad=0.0,
precession_rate_hz=0.0,
spin_rate_hz=1.0)
sim.generate_spin2ecl_quaternions(scanning_strategy=sstr, delta_time_s=0.5)
instr = lbs.InstrumentInfo(spin_boresight_angle_rad=np.deg2rad(15.0))
detector_quat = np.array([[0.0, 0.0, 0.0, 1.0]])
det2ecl_quats = lbs.get_det2ecl_quaternions(
obs,
spin2ecliptic_quats=sim.spin2ecliptic_quats,
detector_quats=detector_quat,
bore2spin_quat=instr.bore2spin_quat,
)
ecl2det_quats = lbs.get_ecl2det_quaternions(
obs,
spin2ecliptic_quats=sim.spin2ecliptic_quats,
detector_quats=detector_quat,
bore2spin_quat=instr.bore2spin_quat,
)
identity = np.array([0, 0, 0, 1])
det2ecl_quats = det2ecl_quats.reshape(-1, 4)
ecl2det_quats = ecl2det_quats.reshape(-1, 4)
for i in range(det2ecl_quats.shape[0]):
# Check that the two quaternions (ecl2det and det2ecl) are
# actually one the inverse of the other
quat = np.copy(det2ecl_quats[i, :])
lbs.quat_right_multiply(quat, *ecl2det_quats[i, :])
assert np.allclose(quat, identity)
def test_simulation_pointings_spinning(tmp_path):
sim = lbs.Simulation(base_path=tmp_path / "simulation_dir",
start_time=0.0,
duration_s=61.0)
fakedet = create_fake_detector(sampling_rate_hz=50.0)
sim.create_observations(detectors=[fakedet],
num_of_obs_per_detector=1,
split_list_over_processes=False)
assert len(sim.observations) == 1
obs = sim.observations[0]
sstr = lbs.SpinningScanningStrategy(spin_sun_angle_rad=0.0,
precession_rate_hz=0.0,
spin_rate_hz=1.0)
sim.generate_spin2ecl_quaternions(scanning_strategy=sstr, delta_time_s=0.5)
instr = lbs.InstrumentInfo(spin_boresight_angle_rad=np.deg2rad(15.0))
pointings_and_polangle = lbs.get_pointings(
obs,
spin2ecliptic_quats=sim.spin2ecliptic_quats,
detector_quats=np.array([[0.0, 0.0, 0.0, 1.0]]),
bore2spin_quat=instr.bore2spin_quat,
)
colatitude = pointings_and_polangle[..., 0]
reference_spin2ecliptic_file = Path(
__file__).parent / "reference_spin2ecl.txt.gz"
reference = np.loadtxt(reference_spin2ecliptic_file)
assert np.allclose(sim.spin2ecliptic_quats.quats, reference)
reference_pointings_file = Path(
__file__).parent / "reference_pointings.txt.gz"
reference = np.loadtxt(reference_pointings_file)
assert np.allclose(pointings_and_polangle[0, :, :], reference)
# Check that the colatitude does not depart more than ±15° from
# the Ecliptic
assert np.allclose(np.rad2deg(np.max(colatitude)), 90 + 15, atol=0.01)
assert np.allclose(np.rad2deg(np.min(colatitude)), 90 - 15, atol=0.01)
sim.flush()
import litebird_sim as lbs
sim = lbs.Simulation(base_path="/tmp/destriper_output",
start_time=0,
duration_s=86400.0)
sim.generate_spin2ecl_quaternions(
scanning_strategy=lbs.SpinningScanningStrategy(
spin_sun_angle_rad=np.deg2rad(30), # CORE-specific parameter
spin_rate_hz=0.5 / 60, # Ditto
# We use astropy to convert the period (4 days) in
# seconds
precession_rate_hz=1.0 / (4 * u.day).to("s").value,
))
instr = lbs.InstrumentInfo(name="core",
spin_boresight_angle_rad=np.deg2rad(65))
# We create two detectors, whose polarization angles are separated by π/2
sim.create_observations(
detectors=[
lbs.DetectorInfo(name="0A", sampling_rate_hz=10),
lbs.DetectorInfo(name="0B",
sampling_rate_hz=10,
quat=lbs.quat_rotation_z(np.pi / 2)),
],
dtype_tod=np.float64,
n_blocks_time=lbs.MPI_COMM_WORLD.size,
split_list_over_processes=False,
)
# Generate some white noise
def test_solar_dipole_fit(tmpdir):
tmpdir = Path(tmpdir)
test = unittest.TestCase()
# The purpose of this test is to simulate the motion of the spacecraft
# for one year (see `time_span_s`) and produce *two* timelines: the first
# is associated with variables `*_s_o` and refers to the case of a nonzero
# velocity of the Solar System, and the second is associated with variables
# `*_o` and assumes that the reference frame of the Solar System is the
# same as the CMB's (so that there is no dipole).
start_time = Time("2022-01-01")
time_span_s = 365 * 24 * 3600
nside = 256
sampling_hz = 1
sim = lbs.Simulation(start_time=start_time, duration_s=time_span_s)
scanning = lbs.SpinningScanningStrategy(
spin_sun_angle_rad=0.785_398_163_397_448_3,
precession_rate_hz=8.664_850_513_998_931e-05,
spin_rate_hz=0.000_833_333_333_333_333_4,
start_time=start_time,
)
spin2ecliptic_quats = scanning.generate_spin2ecl_quaternions(
start_time, time_span_s, delta_time_s=7200
)
instr = lbs.InstrumentInfo(
boresight_rotangle_rad=0.0,
spin_boresight_angle_rad=0.872_664_625_997_164_8,
spin_rotangle_rad=3.141_592_653_589_793,
)
det = lbs.DetectorInfo(
name="Boresight_detector",
sampling_rate_hz=sampling_hz,
bandcenter_ghz=100.0,
quat=[0.0, 0.0, 0.0, 1.0],
)
(obs_s_o,) = sim.create_observations(detectors=[det])
(obs_o,) = sim.create_observations(detectors=[det])
pointings = lbs.scanning.get_pointings(
obs_s_o,
spin2ecliptic_quats=spin2ecliptic_quats,
detector_quats=[det.quat],
bore2spin_quat=instr.bore2spin_quat,
)
orbit_s_o = lbs.SpacecraftOrbit(obs_s_o.start_time)
orbit_o = lbs.SpacecraftOrbit(obs_o.start_time, solar_velocity_km_s=0.0)
assert orbit_s_o.solar_velocity_km_s == 369.8160
assert orbit_o.solar_velocity_km_s == 0.0
pos_vel_s_o = lbs.spacecraft_pos_and_vel(orbit_s_o, obs_s_o, delta_time_s=86400.0)
pos_vel_o = lbs.spacecraft_pos_and_vel(orbit_o, obs_o, delta_time_s=86400.0)
assert pos_vel_s_o.velocities_km_s.shape == (366, 3)
assert pos_vel_o.velocities_km_s.shape == (366, 3)
lbs.add_dipole_to_observations(
obs_s_o, pointings, pos_vel_s_o, dipole_type=lbs.DipoleType.LINEAR
)
lbs.add_dipole_to_observations(
obs_o, pointings, pos_vel_o, dipole_type=lbs.DipoleType.LINEAR
)
npix = hp.nside2npix(nside)
pix_indexes = hp.ang2pix(nside, pointings[0, :, 0], pointings[0, :, 1])
h = np.zeros(npix)
m = np.zeros(npix)
map_s_o = np.zeros(npix)
map_o = np.zeros(npix)
bin_map(
tod=obs_s_o.tod,
pixel_indexes=pix_indexes,
binned_map=map_s_o,
accum_map=m,
hit_map=h,
)
import healpy
healpy.write_map(tmpdir / "map_s_o.fits.gz", map_s_o, overwrite=True)
bin_map(
tod=obs_o.tod,
pixel_indexes=pix_indexes,
binned_map=map_o,
accum_map=m,
hit_map=h,
)
healpy.write_map(tmpdir / "map_o.fits.gz", map_o, overwrite=True)
dip_map = map_s_o - map_o
assert np.abs(np.nanmean(map_s_o) * 1e6) < 1
assert np.abs(np.nanmean(map_o) * 1e6) < 1
assert np.abs(np.nanmean(dip_map) * 1e6) < 1
dip_map[np.isnan(dip_map)] = healpy.UNSEEN
mono, dip = hp.fit_dipole(dip_map)
r = hp.Rotator(coord=["E", "G"])
l, b = hp.vec2ang(r(dip), lonlat=True)
# Amplitude, longitude and latitude
test.assertAlmostEqual(np.sqrt(np.sum(dip ** 2)) * 1e6, 3362.08, 1)
test.assertAlmostEqual(l[0], 264.021, 1)
test.assertAlmostEqual(b[0], 48.253, 1)
def test_destriper(tmp_path):
sim = lbs.Simulation(base_path=tmp_path / "destriper_output",
start_time=0,
duration_s=86400.0)
sim.generate_spin2ecl_quaternions(
scanning_strategy=lbs.SpinningScanningStrategy(
spin_sun_angle_rad=np.deg2rad(30), # CORE-specific parameter
spin_rate_hz=0.5 / 60, # Ditto
# We use astropy to convert the period (4 days) in
# seconds
precession_rate_hz=1.0 / (4 * u.day).to("s").value,
))
instr = lbs.InstrumentInfo(name="core",
spin_boresight_angle_rad=np.deg2rad(65))
sim.create_observations(
detectors=[
lbs.DetectorInfo(name="0A", sampling_rate_hz=10),
lbs.DetectorInfo(name="0B",
sampling_rate_hz=10,
quat=lbs.quat_rotation_z(np.pi / 2)),
],
# num_of_obs_per_detector=lbs.MPI_COMM_WORLD.size,
dtype_tod=np.float64,
n_blocks_time=lbs.MPI_COMM_WORLD.size,
split_list_over_processes=False,
)
# Generate some white noise
rs = RandomState(MT19937(SeedSequence(123456789)))
for curobs in sim.observations:
curobs.tod *= 0.0
curobs.tod += rs.randn(*curobs.tod.shape)
params = lbs.DestriperParameters(
nside=16,
nnz=3,
baseline_length=100,
iter_max=10,
return_hit_map=True,
return_binned_map=True,
return_destriped_map=True,
return_npp=True,
return_invnpp=True,
return_rcond=True,
)
results = lbs.destripe(sim, instr, params=params)
ref_map_path = Path(__file__).parent / "destriper_reference"
hit_map_filename = ref_map_path / "destriper_hit_map.fits.gz"
# healpy.write_map(hit_map_filename, results.hit_map, dtype="int32", overwrite=True)
np.testing.assert_allclose(
results.hit_map,
healpy.read_map(hit_map_filename, field=None, dtype=np.int32))
binned_map_filename = ref_map_path / "destriper_binned_map.fits.gz"
# healpy.write_map(
# binned_map_filename,
# results.binned_map,
# dtype=list((np.float32 for i in range(3))),
# overwrite=True,
# )
ref_binned = healpy.read_map(binned_map_filename,
field=None,
dtype=list((np.float32 for i in range(3))))
assert results.binned_map.shape == ref_binned.shape
np.testing.assert_allclose(results.binned_map,
ref_binned,
rtol=1e-2,
atol=1e-3)
destriped_map_filename = ref_map_path / "destriper_destriped_map.fits.gz"
# healpy.write_map(
# destriped_map_filename,
# results.destriped_map,
# dtype=list((np.float32 for i in range(3))),
# overwrite=True,
# )
ref_destriped = healpy.read_map(destriped_map_filename,
field=None,
dtype=list((np.float32 for i in range(3))))
assert results.destriped_map.shape == ref_destriped.shape
np.testing.assert_allclose(results.destriped_map,
ref_destriped,
rtol=1e-2,
atol=1e-3)
npp_filename = ref_map_path / "destriper_npp.fits.gz"
# healpy.write_map(
# npp_filename,
# results.npp,
# dtype=list((np.float32 for i in range(6))),
# overwrite=True,
# )
ref_npp = healpy.read_map(npp_filename,
field=None,
dtype=list((np.float32 for i in range(6))))
assert results.npp.shape == ref_npp.shape
np.testing.assert_allclose(results.npp, ref_npp, rtol=1e-2, atol=1e-3)
invnpp_filename = ref_map_path / "destriper_invnpp.fits.gz"
# healpy.write_map(
# invnpp_filename,
# results.invnpp,
# dtype=list((np.float32 for i in range(6))),
# overwrite=True,
# )
ref_invnpp = healpy.read_map(invnpp_filename,
field=None,
dtype=list((np.float32 for i in range(6))))
assert results.invnpp.shape == ref_invnpp.shape
np.testing.assert_allclose(results.invnpp,
ref_invnpp,
rtol=1e-2,
atol=1e-3)
rcond_filename = ref_map_path / "destriper_rcond.fits.gz"
# healpy.write_map(
# rcond_filename,
# results.rcond,
# dtype=np.float32,
# overwrite=True,
# )
assert np.allclose(
results.rcond,
healpy.read_map(rcond_filename, field=None, dtype=np.float32))
def test_scan_map():
# The purpose of this test is to simulate the motion of the spacecraft
# for one year (see `time_span_s`) and produce *two* maps: the first
# is associated with the Observation `obs1` and is built using
# `scan_map_in_observations` and `make_bin_map`, the second is associated
# the Observation `obs2` and is built directly filling in the test
# `tod`, `psi` and `pixind` and then using `make_bin_map`
# In the final test `out_map1` is compared with both `out_map2` and the
# input map. Both simulations use two orthogonal detectors at the boresight
# and input maps generated with `np.random.normal`.
start_time = 0
time_span_s = 365 * 24 * 3600
nside = 16
sampling_hz = 1
hwp_radpsec = 4.084_070_449_666_731
npix = hp.nside2npix(nside)
sim = lbs.Simulation(start_time=start_time, duration_s=time_span_s)
scanning = lbs.SpinningScanningStrategy(
spin_sun_angle_rad=0.785_398_163_397_448_3,
precession_rate_hz=8.664_850_513_998_931e-05,
spin_rate_hz=0.000_833_333_333_333_333_4,
start_time=start_time,
)
spin2ecliptic_quats = scanning.generate_spin2ecl_quaternions(
start_time, time_span_s, delta_time_s=7200)
instr = lbs.InstrumentInfo(
boresight_rotangle_rad=0.0,
spin_boresight_angle_rad=0.872_664_625_997_164_8,
spin_rotangle_rad=3.141_592_653_589_793,
)
detT = lbs.DetectorInfo(
name="Boresight_detector_T",
sampling_rate_hz=sampling_hz,
bandcenter_ghz=100.0,
quat=[0.0, 0.0, 0.0, 1.0],
)
detB = lbs.DetectorInfo(
name="Boresight_detector_B",
sampling_rate_hz=sampling_hz,
bandcenter_ghz=100.0,
quat=[0.0, 0.0, 1.0 / np.sqrt(2.0), 1.0 / np.sqrt(2.0)],
)
np.random.seed(seed=123_456_789)
maps = np.random.normal(0, 1, (3, npix))
in_map = {"Boresight_detector_T": maps, "Boresight_detector_B": maps}
(obs1, ) = sim.create_observations(detectors=[detT, detB])
(obs2, ) = sim.create_observations(detectors=[detT, detB])
pointings = lbs.scanning.get_pointings(
obs1,
spin2ecliptic_quats=spin2ecliptic_quats,
detector_quats=[detT.quat, detB.quat],
bore2spin_quat=instr.bore2spin_quat,
)
lbs.scan_map_in_observations(obs1,
pointings,
hwp_radpsec,
in_map,
fill_psi_and_pixind_in_obs=True)
out_map1 = lbs.make_bin_map(obs1, nside).T
times = obs2.get_times()
obs2.pixind = np.empty(obs2.tod.shape, dtype=np.int32)
obs2.psi = np.empty(obs2.tod.shape)
for idet in range(obs2.n_detectors):
obs2.pixind[idet, :] = hp.ang2pix(nside, pointings[idet, :, 0],
pointings[idet, :, 1])
obs2.psi[idet, :] = np.mod(
pointings[idet, :, 2] + 2 * times * hwp_radpsec, 2 * np.pi)
for idet in range(obs2.n_detectors):
obs2.tod[idet, :] = (
maps[0, obs2.pixind[idet, :]] +
np.cos(2 * obs2.psi[idet, :]) * maps[1, obs2.pixind[idet, :]] +
np.sin(2 * obs2.psi[idet, :]) * maps[2, obs2.pixind[idet, :]])
out_map2 = lbs.make_bin_map(obs2, nside).T
np.testing.assert_allclose(out_map1,
in_map["Boresight_detector_T"],
rtol=1e-6,
atol=1e-6)
np.testing.assert_allclose(out_map1, out_map2, rtol=1e-6, atol=1e-6)
def main():
warnings.filterwarnings("ignore", category=ErfaWarning)
sim = lbs.Simulation(
parameter_file=sys.argv[1],
name="Observation of planets",
description="""
This report contains the result of a simulation of the observation
of the sky, particularly with respect to the observation of planets.
""",
)
params = load_parameters(sim)
if lbs.MPI_ENABLED:
log.info("Using MPI with %d processes", lbs.MPI_COMM_WORLD.size)
else:
log.info("Not using MPI, serial execution")
log.info("Generating the quaternions")
scanning_strategy = read_scanning_strategy(
sim.parameters["scanning_strategy"], sim.imo, sim.start_time)
sim.generate_spin2ecl_quaternions(
scanning_strategy=scanning_strategy,
delta_time_s=params.spin2ecl_delta_time_s)
log.info("Creating the observations")
instr = lbs.InstrumentInfo(
name="instrum",
spin_boresight_angle_rad=params.spin_boresight_angle_rad)
detector = lbs.DetectorInfo(
sampling_rate_hz=params.detector_sampling_rate_hz)
conversions = [
("years", astropy.units.year),
("year", astropy.units.year),
("days", astropy.units.day),
("day", astropy.units.day),
("hours", astropy.units.hour),
("hour", astropy.units.hour),
("minutes", astropy.units.minute),
("min", astropy.units.minute),
("sec", astropy.units.second),
("s", astropy.units.second),
("km", astropy.units.kilometer),
("Km", astropy.units.kilometer),
("au", astropy.units.au),
("AU", astropy.units.au),
("deg", astropy.units.deg),
("rad", astropy.units.rad),
]
def conversion(x, new_unit):
if isinstance(x, str):
for conv_str, conv_unit in conversions:
if x.endswith(" " + conv_str):
value = float(x.replace(conv_str, ""))
return (value * conv_unit).to(new_unit).value
break
else:
return float(x)
sim_params = sim.parameters["simulation"]
durations = ["duration_s", "duration_of_obs_s"]
for dur in durations:
sim_params[dur] = conversion(sim_params[dur], "s")
delta_t_s = sim_params["duration_of_obs_s"]
sim.create_observations(
detectors=[detector],
num_of_obs_per_detector=int(sim_params["duration_s"] /
sim_params["duration_of_obs_s"]),
)
#################################################################
# Here begins the juicy part
log.info("The loop starts on %d processes", lbs.MPI_COMM_WORLD.size)
sky_hitmap = np.zeros(healpy.nside2npix(params.output_nside),
dtype=np.int32)
detector_hitmap = np.zeros(healpy.nside2npix(params.output_nside),
dtype=np.int32)
dist_map_m2 = np.zeros(len(detector_hitmap))
iterator = tqdm
if lbs.MPI_ENABLED and lbs.MPI_COMM_WORLD.rank != 0:
iterator = lambda x: x
# Time variable inizialized at the beginning of the simulation
t = 0.0
for obs in iterator(sim.observations):
solar_system_ephemeris.set("builtin")
times = obs.get_times(astropy_times=True)
# We only compute the planet's position for the first sample in
# the observation and then assume that it does not move
# significantly. (In Ecliptic coordinates, Jupiter moves by
# fractions of an arcmin over a time span of one hour)
time0 = times[0]
icrs_pos = get_ecliptic_vec(
get_body_barycentric(params.planet_name, time0))
earth_pos = get_ecliptic_vec(get_body_barycentric("earth", time0))
# Move the spacecraft to L2
L2_pos = earth_pos * (
1.0 + params.earth_L2_distance_km / norm(earth_pos).to("km").value)
# Creating a Lissajous orbit
R1 = conversion(params.radius_au[0], "au")
R2 = conversion(params.radius_au[1], "au")
phi1_t = params.L2_orbital_velocity_rad_s[0] * t
phi2_t = params.L2_orbital_velocity_rad_s[1] * t
phase = conversion(params.phase_rad, "rad")
orbit_pos = np.array([
-R1 * np.sin(np.arctan(L2_pos[1] / L2_pos[0])) * np.cos(phi1_t),
R1 * np.cos(np.arctan(L2_pos[1] / L2_pos[0])) * np.cos(phi1_t),
R2 * np.sin(phi2_t + phase),
])
orbit_pos = astropy.units.Quantity(orbit_pos, unit="AU")
# Move the spacecraft to a Lissajous orbit around L2
sat_pos = orbit_pos + L2_pos
# Compute the distance between the spacecraft and the planet
distance_m = norm(sat_pos - icrs_pos).to("m").value
# This is the direction of the solar system body with respect
# to the spacecraft, in Ecliptic coordinates
ecl_vec = (icrs_pos - sat_pos).value
# The variable ecl_vec is a 3-element vector. We normalize it so
# that it has length one (using the L_2 norm, hence ord=2)
ecl_vec /= np.linalg.norm(ecl_vec, axis=0, ord=2)
# Convert the matrix to a N×3 shape by repeating the vector:
# planets move slowly, so we assume that the planet stays fixed
# during this observation.
ecl_vec = np.repeat(ecl_vec.reshape(1, 3), len(times), axis=0)
# Calculate the quaternions that convert the Ecliptic
# reference system into the detector's reference system
quats = lbs.get_ecl2det_quaternions(
obs,
sim.spin2ecliptic_quats,
detector_quats=[detector.quat],
bore2spin_quat=instr.bore2spin_quat,
)
# Make room for the xyz vectors in the detector's reference frame
det_vec = np.empty_like(ecl_vec)
# Do the rotation!
lbs.all_rotate_vectors(det_vec, quats[0], ecl_vec)
pixidx = healpy.vec2pix(params.output_nside, det_vec[:, 0],
det_vec[:, 1], det_vec[:, 2])
bincount = np.bincount(pixidx, minlength=len(detector_hitmap))
detector_hitmap += bincount
dist_map_m2 += bincount / ((4 * np.pi * (distance_m**2))**2)
pointings = lbs.get_pointings(obs, sim.spin2ecliptic_quats,
[detector.quat], instr.bore2spin_quat)[0]
pixidx = healpy.ang2pix(params.output_nside, pointings[:, 0],
pointings[:, 1])
bincount = np.bincount(pixidx, minlength=len(sky_hitmap))
sky_hitmap += bincount
# updating the time variable
t += delta_t_s
if lbs.MPI_ENABLED:
sky_hitmap = lbs.MPI_COMM_WORLD.allreduce(sky_hitmap)
detector_hitmap = lbs.MPI_COMM_WORLD.allreduce(detector_hitmap)
dist_map_m2 = lbs.MPI_COMM_WORLD.allreduce(dist_map_m2)
time_map_s = detector_hitmap / params.detector_sampling_rate_hz
dist_map_m2[dist_map_m2 > 0] = np.power(dist_map_m2[dist_map_m2 > 0], -0.5)
obs_time_per_radius_s = [
time_per_radius(time_map_s, angular_radius_rad=np.deg2rad(radius_deg))
for radius_deg in params.radii_deg
]
if lbs.MPI_COMM_WORLD.rank == 0:
# Create a plot of the observation time of the planet as a
# function of the angular radius
fig, ax = plt.subplots()
ax.loglog(params.radii_deg, obs_time_per_radius_s)
ax.set_xlabel("Radius [deg]")
ax.set_ylabel("Observation time [s]")
# Create a map showing how the observation time is distributed on
# the sphere (in the reference frame of the detector)
healpy.orthview(time_map_s,
title="Time spent observing the source",
unit="s")
if scanning_strategy.spin_rate_hz != 0:
spin_period_min = 1.0 / (60.0 * scanning_strategy.spin_rate_hz)
else:
spin_period_min = 0.0
if scanning_strategy.precession_rate_hz != 0:
precession_period_min = 1.0 / (
60.0 * scanning_strategy.precession_rate_hz)
else:
precession_period_min = 0.0
sim.append_to_report(
"""
## Scanning strategy parameters
Parameter | Value
--------- | --------------
Angle between the spin axis and the Sun-Earth axis | {{ sun_earth_angle_deg }} deg
Angle between the spin axis and the boresight | {{ spin_boresight_angle_deg }} deg
Precession period | {{ precession_period_min }} min
Spin period | {{ spin_period_min }} min
## Observation of {{ params.planet_name | capitalize }}
The overall time spent in the map is {{ overall_time_s }} seconds.
The time resolution of the simulation was {{ delta_time_s }} seconds.
Angular radius [deg] | Time spent [s]
-------------------- | ------------------------
{% for row in radius_vs_time_s -%}
{{ "%.1f"|format(row[0]) }} | {{ "%.1f"|format(row[1]) }}
{% endfor -%}
""",
figures=[(plt.gcf(), "detector_hitmap.png"),
(fig, "radius_vs_time.svg")],
params=params,
overall_time_s=np.sum(detector_hitmap) /
params.detector_sampling_rate_hz,
radius_vs_time_s=list(zip(params.radii_deg,
obs_time_per_radius_s)),
delta_time_s=1.0 / params.detector_sampling_rate_hz,
sun_earth_angle_deg=np.rad2deg(
scanning_strategy.spin_sun_angle_rad),
spin_boresight_angle_deg=np.rad2deg(
params.spin_boresight_angle_rad),
precession_period_min=precession_period_min,
spin_period_min=spin_period_min,
det=detector,
)
healpy.write_map(
params.output_map_file_name,
(detector_hitmap, time_map_s, dist_map_m2, sky_hitmap),
coord="DETECTOR",
column_names=["HITS", "OBSTIME", "SQDIST", "SKYHITS"],
column_units=["", "s", "m^2", ""],
dtype=[np.int32, np.float32, np.float64, np.int32],
overwrite=True,
)
np.savetxt(
params.output_table_file_name,
np.array(list(zip(params.radii_deg, obs_time_per_radius_s))),
fmt=["%.2f", "%.5e"],
)
with (sim.base_path / "parameters.json").open("wt") as outf:
time_value = scanning_strategy.start_time
if not isinstance(time_value, (int, float)):
time_value = str(time_value)
json.dump(
{
"scanning_strategy": {
"spin_sun_angle_rad":
scanning_strategy.spin_sun_angle_rad,
"precession_rate_hz":
scanning_strategy.precession_rate_hz,
"spin_rate_hz": scanning_strategy.spin_rate_hz,
"start_time": time_value,
},
"detector": {
"sampling_rate_hz": params.detector_sampling_rate_hz
},
"planet": {
"name": params.planet_name
},
},
outf,
indent=2,
)
sim.flush()
precession_rate_hz=0,
spin_rate_hz=1 / 60,
start_time=start_time,
)
# The spacecraft spins pretty fast (once per minute!), so we
# need to pick delta_time_s ≪ 1/spin_rate_hz
spin2ecliptic_quats = scanning.generate_spin2ecl_quaternions(start_time,
time_span_s,
delta_time_s=5.0)
# We simulate an instrument whose boresight is perpendicular to
# the spin axis.
instr = lbs.InstrumentInfo(
boresight_rotangle_rad=0.0,
spin_boresight_angle_rad=np.deg2rad(90),
spin_rotangle_rad=np.deg2rad(75),
)
# A simple detector looking along the boresight direction
det = lbs.DetectorInfo(
name="Boresight_detector",
sampling_rate_hz=sampling_hz,
bandcenter_ghz=100.0,
)
(obs, ) = sim.create_observations(detectors=[det])
pointings = lbs.scanning.get_pointings(
obs,
spin2ecliptic_quats=spin2ecliptic_quats,
detector_quats=[det.quat],
