def test_era(self):
"""Comare ERA relative to erfa.era00 test case."""
t = Time(2400000.5, 54388.0, format='jd', location=(0, 0), scale='ut1')
era = t.earth_rotation_angle()
expected = 0.4022837240028158102 * u.radian
# Without the TIO locator/polar motion, this should be close already.
assert np.abs(era - expected) < 1e-10 * u.radian
# And with it, one should reach full precision.
sp = erfa.sp00(t.tt.jd1, t.tt.jd2)
iers_table = iers.earth_orientation_table.get()
xp, yp = [c.to_value(u.rad) for c in iers_table.pm_xy(t)]
r = erfa.rx(-yp, erfa.ry(-xp, erfa.rz(sp, np.eye(3))))
expected1 = expected + (np.arctan2(r[0, 1], r[0, 0]) << u.radian)
assert np.abs(era - expected1) < 1e-12 * u.radian
# Now try at a longitude different from 0.
t2 = Time(2400000.5,
54388.0,
format='jd',
location=(45, 0),
scale='ut1')
era2 = t2.earth_rotation_angle()
r2 = erfa.rz(np.deg2rad(45), r)
expected2 = expected + (np.arctan2(r2[0, 1], r2[0, 0]) << u.radian)
assert np.abs(era2 - expected2) < 1e-12 * u.radian
GST = erfa.anp(erfa.gmst82(DJMJD0 + DATE, TUT) + EE)
print("GST = %.17f radians" % GST)
print(" = %.17f degrees" % math.degrees(GST))
print(" = %s%dd%dm%d.%ds" % erfa.a2af(6, GST))
print(" = %s%dh%dm%d.%ds" % erfa.a2tf(6, GST))
# Form celestial-terrestrial matrix (no polar motion yet).
##RC2TI = erfa.cr(RNPB)
##RC2TI = erfa.rz(GST, RC2TI)
RC2TI = erfa.rz(GST, RNPB)
print("celestial to terrestrial matrix (no polar motion)")
pprint(RC2TI)
# Polar motion matrix (TIRS->ITRS, IERS 1996).
RPOM = erfa.ir()
RPOM = erfa.rx(-YP, RPOM)
RPOM = erfa.ry(-XP, RPOM)
# Form celestial-terrestrial matrix (including polar motion).
RC2IT = erfa.rxr(RPOM, RC2TI)
print("celestial to terrestrial matrix (including polar motion)")
pprint(RC2IT)
##A = scipy.matrix(RC2IT)
print('''
============================================
IAU 2000A, CIO based, using classical angles
============================================
''')
# CIP and CIO, IAU 2000A.
GST = erfa.anp(erfa.gmst82(DJMJD0+DATE, TUT) + EE)
print("GST = %.17f radians"%GST)
print(" = %.17f degrees"%math.degrees(GST))
print(" = %s%dd%dm%d.%ds"%erfa.a2af(6, GST))
print(" = %s%dh%dm%d.%ds"%erfa.a2tf(6, GST))
# Form celestial-terrestrial matrix (no polar motion yet).
##RC2TI = erfa.cr(RNPB)
##RC2TI = erfa.rz(GST, RC2TI)
RC2TI = erfa.rz(GST, RNPB)
print("celestial to terrestrial matrix (no polar motion)")
pprint(RC2TI)
# Polar motion matrix (TIRS->ITRS, IERS 1996).
RPOM = erfa.ir()
RPOM = erfa.rx(-YP, RPOM)
RPOM = erfa.ry(-XP, RPOM)
# Form celestial-terrestrial matrix (including polar motion).
RC2IT = erfa.rxr(RPOM, RC2TI)
print("celestial to terrestrial matrix (including polar motion)")
pprint(RC2IT)
##A = scipy.matrix(RC2IT)
print('''
============================================
IAU 2000A, CIO based, using classical angles
============================================
''')
# CIP and CIO, IAU 2000A.
print(" = %s"%c, end='')
print("%dd%dm%d.%ds"%tuple(a))
for c,a in erfa.a2tf(6, GST):
print(" = %s"%c, end='')
print("%dh%dm%d.%ds"%tuple(a))
# Form celestial-terrestrial matrix (no polar motion yet).
##RC2TI = erfa.cr(RNPB)
##RC2TI = erfa.rz(GST, RC2TI)
RC2TI = erfa.rz(GST, RNPB)
print("celestial to terrestrial matrix (no polar motion)")
pprint(RC2TI)
# Polar motion matrix (TIRS->ITRS, IERS 1996).
RPOM = np.array([np.identity(3)]) ##erfa.ir()
RPOM = erfa.rx(np.array([-YP]), RPOM)
RPOM = erfa.ry(np.array([-XP]), RPOM)
# Form celestial-terrestrial matrix (including polar motion).
RC2IT = erfa.rxr(RPOM, RC2TI)
print("celestial to terrestrial matrix (including polar motion)")
pprint(RC2IT)
##A = scipy.matrix(RC2IT)
print('''
============================================
IAU 2000A, CIO based, using classical angles
============================================
''')
# CIP and CIO, IAU 2000A.