def test_IERS_B_agree_with_IERS_Auto_dX():
A = IERS_Auto.open()
B = IERS_B.open(download_file(IERS_B_URL, cache=True))
mjd = B["MJD"].to(u.day).value
A.pm_xy(mjd) # ensure that data is available for this date
# Let's get rid of some trouble values and see if they agree on a restricted subset
# IERS Auto ends with a bunch of 1e20 values meant as sentinels (?)
ok_A = abs(A["dX_2000A_B"]) < 1e6 * u.marcsec
# For some reason IERS B starts with zeros up to MJD 45700? IERS Auto doesn't match this
# ok_A &= A['MJD'] > 45700*u.d
# Maybe the old values are bogus?
ok_A &= A["MJD"] > 50000 * u.d
mjds_A = A["MJD"][ok_A].to(u.day).value
i_B = np.searchsorted(B["MJD"].to(u.day).value, mjds_A)
assert np.all(np.diff(i_B) == 1), "Valid region not contiguous"
assert_equal(A["MJD"][ok_A], B["MJD"][i_B], "MJDs don't make sense")
for tag in ["dX_2000A", "dY_2000A"]:
assert_allclose(
A[tag + "_B"][ok_A].to(u.marcsec).value,
B[tag][i_B].to(u.marcsec).value,
atol=1e-5,
rtol=1e-3,
err_msg=
"IERS A-derived IERS B {} values don't match current IERS B values"
.format(tag),
)
def test_IERS_B_builtin_agree_with_IERS_Auto_dX():
A = IERS_Auto.open()
B = IERS_B.open(IERS_B_FILE)
mjd = B["MJD"].to(u.day).value
A.pm_xy(mjd) # ensure that data is available for these dates
# We're going to look up the OK auto values in the B table
ok_A = A["MJD"] < B["MJD"][-1]
# Let's get rid of some trouble values and see if they agree on a restricted subset
# IERS Auto ends with a bunch of 1e20 values meant as sentinels (?)
ok_A &= abs(A["dX_2000A_B"]) < 1e6 * u.marcsec
# For some reason IERS B starts with zeros up to MJD 45700? IERS Auto doesn't match this
ok_A &= A["MJD"] > 45700 * u.d
# Maybe the old values are bogus?
ok_A &= A["MJD"] > 50000 * u.d
mjds_A = A["MJD"][ok_A].to(u.day).value
i_B = np.searchsorted(B["MJD"].to(u.day).value, mjds_A)
assert np.all(np.diff(i_B) == 1), "Valid region not contiguous"
assert_equal(A["MJD"][ok_A], B["MJD"][i_B], "MJDs don't make sense")
assert_allclose(
A["dX_2000A_B"][ok_A].to(u.marcsec).value,
B["dX_2000A"][i_B].to(u.marcsec).value,
atol=1e-5,
rtol=1e-3,
err_msg=
"IERS B values included in IERS A (dX_2000A) don't match IERS_B_FILE values",
)
def test_IERS_B_all_in_IERS_Auto():
B = IERS_B.open(download_file(IERS_B_URL, cache=True))
mjd = B["MJD"].to(u.day).value
A = IERS_Auto.open()
A.pm_xy(mjd) # ensure that data is available for this date
i_A = np.searchsorted(A["MJD"].to(u.day).value, mjd)
assert_equal(A["dX_2000A_B"][i_A], B["dX_2000A"])
def test_IERS_B_builtin_agree_with_IERS_Auto():
"""The UT1-UTC, PM_X, and PM_Y values are correctly copied"""
A = IERS_Auto.open()
B = IERS_B.open(IERS_B_FILE)
mjd = B["MJD"].to(u.day).value
A.pm_xy(mjd) # ensure that data is available for these dates
# We're going to look up the OK auto values in the B table
ok_A = A["MJD"] < B["MJD"][-1]
# Let's get rid of some trouble values and see if they agree on a restricted subset
# IERS Auto ends with a bunch of 1e20 values meant as sentinels (?)
ok_A &= abs(A["PM_X_B"]) < 1e6 * u.marcsec
# For some reason IERS B starts with zeros up to MJD 45700? IERS Auto doesn't match this
ok_A &= A["MJD"] > 45700 * u.d
# Maybe the old values are bogus?
ok_A &= A["MJD"] > 50000 * u.d
mjds_A = A["MJD"][ok_A].to(u.day).value
i_B = np.searchsorted(B["MJD"].to(u.day).value, mjds_A)
assert np.all(np.diff(i_B) == 1), "Valid region not contiguous"
assert_equal(A["MJD"][ok_A], B["MJD"][i_B], "MJDs don't make sense")
for atag, btag, unit in [
("UT1_UTC_B", "UT1_UTC", u.s),
("PM_X_B", "PM_x", u.arcsec),
("PM_Y_B", "PM_y", u.arcsec),
]:
assert_allclose(
A[atag][ok_A].to(unit).value,
B[btag][i_B].to(unit).value,
atol=1e-5,
rtol=1e-5, # should be exactly equal
err_msg="Inserted IERS B {} values don't match IERS_B_FILE {} values"
.format(atag, btag),
)
def test_IERS_B_agree_with_IERS_Auto():
A = IERS_Auto.open()
B = IERS_B.open(download_file(IERS_B_URL, cache=True))
mjd = B["MJD"].to(u.day).value
A.pm_xy(mjd) # ensure that data is available for this date
# Let's get rid of some trouble values and see if they agree on a restricted subset
# IERS Auto ends with a bunch of 1e20 values meant as sentinels (?)
ok_A = abs(A["PM_X_B"]) < 1e6 * u.marcsec
# Maybe the old values are bogus?
ok_A &= A["MJD"] > 50000 * u.d
mjds_A = A["MJD"][ok_A].to(u.day).value
i_B = np.searchsorted(B["MJD"].to(u.day).value, mjds_A)
assert np.all(np.diff(i_B) == 1), "Valid region not contiguous"
assert_equal(A["MJD"][ok_A], B["MJD"][i_B], "MJDs don't make sense")
for atag, btag, unit in [
("UT1_UTC_B", "UT1_UTC", u.s), # s, six decimal places
("PM_X_B", "PM_x", u.arcsec),
("PM_Y_B", "PM_y", u.arcsec),
]:
assert_allclose(
A[atag][ok_A].to(unit).value,
B[btag][i_B].to(unit).value,
atol=1e-5,
rtol=1e-5, # should be "close enough"
err_msg="Inserted IERS B {} values don't match IERS_B_URL {} values"
.format(atag, btag),
)
def get_iers_up_to_date(mjd=Time.now().mjd - 45.0):
"""
Update the IERS B table to include MJD (defaults to 45 days ago) and open IERS_Auto
"""
# First clear the IERS_Auto table
IERS_Auto.iers_table = None
if mjd > Time.now().mjd:
raise ValueError("IERS B data requested for future MJD {}".format(mjd))
might_be_old = is_url_in_cache(IERS_B_URL)
iers_b = IERS_B.open(download_file(IERS_B_URL, cache=True))
if might_be_old and iers_b[-1]["MJD"].to_value(u.d) < mjd:
# Try wiping the download and re-downloading
log.info("IERS B Table appears to be old. Attempting to re-download.")
clear_download_cache(IERS_B_URL)
iers_b = IERS_B.open(download_file(IERS_B_URL, cache=True))
if iers_b[-1]["MJD"].to_value(u.d) < mjd:
log.warning("IERS B data not yet available for MJD {}".format(mjd))
# Now open IERS_Auto with no argument, so it should use the IERS_B that we just made sure was up to date
iers_auto = IERS_Auto.open()
if astropy.version.major >= 4:
# Tell astropy to use this table for all future transformations
earth_orientation_table.set(iers_auto)
def test_iers_discrepancies():
iers_auto = IERS_Auto.open()
iers_b = IERS_B.open()
for mjd in [56000, 56500, 57000]:
t = Time(mjd, scale="tdb", format="mjd")
b_x, b_y = iers_b.pm_xy(t)
a_x, a_y = iers_auto.pm_xy(t)
assert abs(a_x - b_x) < 1 * u.marcsec
assert abs(a_y - b_y) < 1 * u.marcsec
def _low_precision_utc_to_ut1(self, jd1, jd2):
"""
When no IERS Bulletin A is available (no internet connection), use low
precision time conversion by assuming UT1-UTC=0 always.
This method mimics `~astropy.coordinates.builtin_frames.utils.get_dut1utc`
"""
try:
if self.mjd * u.day not in IERS_Auto.open()['MJD']:
warnings.warn(IERS_A_WARNING, OldEarthOrientationDataWarning)
return self.delta_ut1_utc
except (AttributeError, ValueError):
warnings.warn(IERS_A_WARNING, OldEarthOrientationDataWarning)
return np.zeros(self.shape)
def test_IERS_B_parameters_loaded_into_IERS_Auto(b_name, a_name):
A = IERS_Auto.open()
A[a_name]
B = IERS_B.open(IERS_B_FILE)
ok_A = A["MJD"] < B["MJD"][-1]
mjds_A = A["MJD"][ok_A].to(u.day).value
i_B = np.searchsorted(B["MJD"].to(u.day).value, mjds_A)
assert_equal(np.diff(i_B), 1, err_msg="Valid region not contiguous")
assert_equal(A["MJD"][ok_A], B["MJD"][i_B], err_msg="MJDs don't make sense")
assert_equal(
A[a_name][ok_A],
B[b_name][i_B],
err_msg="IERS B parameter {} not copied over IERS A parameter {}".format(
b_name, a_name
),
)
except ImportError:
from warnings import warn, simplefilter
simplefilter('always')
warn('Compatible Astropy not found, creating an empty IERS-A table. '
'Install astropy v1.2 or newer for accurate polar motion '
'and UT1 corrections',
ImportWarning)
f.write( " {0., 0., 0.}, // NULL\n")
mjd_min = 0
mjd_max = 0
else:
columns = ['year', 'month', 'day', 'MJD', 'PM_x', 'PM_y', 'UT1_UTC']
iers_table = IERS_Auto.open()[columns].as_array()
# check year
year = iers_table['year'] + 1900
wraps, = np.where(np.ediff1d(year) < 0)
for idx in wraps:
year[idx + 1:] += 100
iers_table['year'] = year
iers_table = iers_table[year >= 2000]
# check MJD
mjds = iers_table['MJD']
mjd_min = int(mjds.min())
mjd_max = int(mjds.max())
# populate factory table