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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
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:
FileName Lrecl Records Explanations
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)
See also: J/A+A/355/398 : Celestial Ephemeris Origin definition (Capitaine+, 2000) Byte-by-byte Description of file: tablea.dat
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 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
Byte-by-byte Description of file: tableb.dat
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
Byte-by-byte Description of file: tablec.dat
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

(End) Patricia Bauer [CDS] 21-Jan-2003
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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