J/A+A/400/1145 Celestial Intermediate Pole & Ephemeris Origin (Capitaine+, 2003)
Expressions for the Celestial Intermediate Pole and Celestial Ephemeris Origin
consistent with the IAU 2000A precession-nutation model.
Capitaine N., Chapront J., Lambert S., Wallace P.T.
<Astron. Astrophys. 400, 1145 (2003)>
=2003A&A...400.1145C 2003A&A...400.1145C
ADC_Keywords: Ephemerides ; Earth
Keywords: astrometry - ephemerides - reference systems - time - Earth rotation
Abstract:
Expressions for the position of the Celestial Intermediate Pole (CIP)
and the Celestial Ephemeris Origin (CEO) in the Geocentric Celestial
Reference System (GCRS) have been computed using the IAU 2000A
precession-nutation. These expressions are for use in the new
transformation between the GCRS and the International Terrestrial
Reference System (ITRS) which is recommended by IAU Resolution B1.8.
Various comparisons and numerical checks have been performed between
the classical and the new transformations based on the IAU 2000A
precession-nutation. These comparisons revealed necessary improvements
to be applied to the classical form of the transformation in order to
achieve the required level of accuracy. Once these improvements are
applied, the consistency between the positions of the CIP in the GCRS
corresponding to the classical and the new transformations is at a
level of a few microarcseconds after one century. This work has
demonstrated that the new method, in addition to providing an explicit
separation between precession-nutation of the equator from Earth
rotation, is more simple, compact and direct than the classical one,
achieving accuracies at the level of a few microarcseconds with
greatly reduced scope for accidental misuse. The resulting expressions
for X, Y and s have been included in the IERS Conventions 2000.
Description:
The tables contain the parameters of the development as functions of
time t (expressed in centuries since J2000.0) for the non-polynomial
part of the Celestial Pole Coordinates X and Y and the Celestial
Ephemeris Origin, in microarcseconds.
X=-16616.99 + 2004191742.88t - 427219.05t2 - 198620.54t3
-46.05t4 + 5.98t5
+Sum_i)j=0,4 [a{s,j})i_*tj*sin(ARG) + a{c,j})i_*cos(ARG)]*tj]
Y=-6950.78 - 25381.99t - 22407250.99t2 + 1842.28t3
+1113.06t4 + 0.99t5
+Sum_i)j=0,4 [b{c,j})i_*tj*cos(ARG) + b{s,j})i_*sin(ARG)]*tj]
s+XY/2=94.0 + 3808.35t - 119.94t2 - 72574.09t3
+27.70t4 + 15.61t5
+Sum_i)j=0,4 [C{s,j})i_*tj*sin(ARG) + C{c,j})i_*cos(ARG)]*tj]
where:
ARG = nl*l + nl'*l' + nF*F + nD*D + nOm*Om +nLMe*LMe + nLV*LV + nLE*LE +
nLMa*LMa + nLJ*LJ + nLS*LS + nLU*LU + nLN*LN +npa*pa
l, l', F, D, Om, LMe, LV, LE, LMa, LJ, LS, LU, LN, pa being the lunisolar
and planetary arguments of the nutation theory.
File Summary:
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Filename Lrecl Records Explanations
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ReadMe 80 . This file
tablea.dat 105 1600 Non-polynomial terms in the development of the
coordinate X(t) of the Celestial Intermediate Pole
in the ICRS compatible with IAU 2000A
precession-nutation model (unit mas)
tableb.dat 105 1275 Non-polynomial terms in the development of the
coordinate Y(t) of the Celestial Intermediate Pole
in the ICRS compatible with IAU 2000A
precession-nutation model (unit mas)
tablec.dat 105 66 Non-polynomial terms in the development of the
quantity s(t)+XY/2 compatible with IAU 2000A
precession-nutation model (unit mas)
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See also:
J/A+A/355/398 : Celestial Ephemeris Origin definition (Capitaine+, 2000)
Byte-by-byte Description of file: tablea.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- N Number of records of order j
6 I1 --- j Order of the Poisson term (power of t)
8- 12 I5 --- i Term number i
14- 24 F11.2 uarcsec asji a{s,j})i coefficient, in micro-arcsec
26- 35 F10.2 uarcsec acji a{c,j})i coefficient, in micro-arcsec
39- 40 I2 --- nl Mean anomaly of the Moon coefficient
44- 45 I2 --- nl' Mean anomaly of the Sun coefficient
49- 50 I2 --- nF L - Omega (L: Mean longitude of the Moon)
coefficient
54- 55 I2 --- nD Mean elongation from the Moon to the Sun
coefficient
59- 60 I2 --- nOm Mean longitude of the ascending node of the
Moon (Omega) coefficient
64- 65 I2 --- nLMe Mean longitude of Mercure coefficient
68- 70 I3 --- nLV Mean longitude of Venus coefficient
73- 75 I3 --- nLE Mean longitude of the Earth coefficient
78- 80 I3 --- nLMa Mean longitude of Mars coefficient
84- 85 I2 --- nLJ Mean longitude of Jupiter coefficient
89- 90 I2 --- nLS Mean longitude of Saturn coefficient
94- 95 I2 --- nLU Mean longitude of Uranus coefficient
99-100 I2 --- nLN Mean longitude of Neptune coefficient
104-105 I2 --- npa Accumulated general precession in longitude
coefficient
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Byte-by-byte Description of file: tableb.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- N Number of records of order j
6 I1 --- j Order of the Poisson term (power of t)
8- 12 I5 --- i Term number i
14- 24 F11.2 uarcsec bsji b{s,j})i coefficient, in micro-arcsec
26- 35 F10.2 uarcsec bcji b{c,j})i coefficient, in micro-arcsec
39- 40 I2 --- nl Mean anomaly of the Moon coefficient
44- 45 I2 --- nl' Mean anomaly of the Sun coefficient
49- 50 I2 --- nF L - Omega (L: Mean longitude of the Moon)
coefficient
54- 55 I2 --- nD Mean elongation from the Moon to the Sun
coefficient
59- 60 I2 --- nOm Mean longitude of the ascending node of the
Moon (Omega) coefficient
64- 65 I2 --- nLMe Mean longitude of Mercure coefficient
68- 70 I3 --- nLV Mean longitude of Venus coefficient
73- 75 I3 --- nLE Mean longitude of the Earth coefficient
78- 80 I3 --- nLMa Mean longitude of Mars coefficient
84- 85 I2 --- nLJ Mean longitude of Jupiter coefficient
89- 90 I2 --- nLS Mean longitude of Saturn coefficient
94- 95 I2 --- nLU Mean longitude of Uranus coefficient
99-100 I2 --- nLN Mean longitude of Neptune coefficient
104-105 I2 --- npa Accumulated general precession in longitude
coefficient
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Byte-by-byte Description of file: tablec.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- N Number of records of order j
6 I1 --- j Order of the Poisson term (power of t)
8- 12 I5 --- i Term number i
14- 24 F11.2 uarcsec Csji C{s,j})i coefficient, in micro-arcsec
26- 35 F10.2 uarcsec Ccji C{c,j})i coefficient, in micro-arcsec
39- 40 I2 --- nl Mean anomaly of the Moon coefficient
44- 45 I2 --- nl' Mean anomaly of the Sun coefficient
49- 50 I2 --- nF L - Omega (L: Mean longitude of the Moon)
coefficient
54- 55 I2 --- nD Mean elongation from the Moon to the Sun
coefficient
59- 60 I2 --- nOm Mean longitude of the ascending node of the
Moon (Omega) coefficient
64- 65 I2 --- nLMe Mean longitude of Mercure coefficient
68- 70 I3 --- nLV Mean longitude of Venus coefficient
73- 75 I3 --- nLE Mean longitude of the Earth coefficient
78- 80 I3 --- nLMa Mean longitude of Mars coefficient
84- 85 I2 --- nLJ Mean longitude of Jupiter coefficient
89- 90 I2 --- nLS Mean longitude of Saturn coefficient
94- 95 I2 --- nLU Mean longitude of Uranus coefficient
99-100 I2 --- nLN Mean longitude of Neptune coefficient
104-105 I2 --- npa Accumulated general precession in longitude
coefficient
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(End) Patricia Bauer [CDS] 21-Jan-2003