J/A+A/459/981 Precession-nutation procedures (IAU 2006) (Wallace+, 2006)
Precession-nutation procedures consistent with IAU 2006 resolutions.
Wallace P.T., Capitaine N.
<Astron. Astrophys. 459, 981 (2006)>
=2006A&A...459..981W 2006A&A...459..981W
ADC_Keywords: Positional data ; Ephemerides ; Earth
Keywords: astrometry - reference systems - ephemerides - celestial mechanics -
time
Abstract:
The 2006 IAU General Assembly has adopted the P03 model of Capitaine
et al. (2003A&A...412..567C 2003A&A...412..567C) recommended by the WG on precession and
the ecliptic (Hilton et al., 2006, Celest. Mech. Dyn. Astron. 94, 351)
to replace the IAU 2000 model, which comprised the Lieske et al.
(1977A&A....58....1L 1977A&A....58....1L) model with adjusted rates. Practical
implementations of this new "IAU 2006" model are therefore required,
involving choices of procedures and algorithms.
The purpose of this paper is to recommend IAU 2006 based
precession-nutation computing procedures, suitable for different
classes of application and achieving high standards of consistency.
Description:
The three tables contain the coefficients of the series developments
for generating the coordinates of the celestial intermediate pole and
the quantity s+XY/2 (and hence s) for the P03 precession model
(Capitaine et al., 2003A&A...412..567C 2003A&A...412..567C) with the IAU 2000A
nutation. Each table contains the coefficients in microarcseconds
(uas) of the series developments (i.e. Fourier and Poisson terms) as
functions of (terrestrial) time t (expressed in centuries since
J2000.0) for the quantities X, Y and s+XY/2, respectively, retaining
all terms where the sum of the absolute values of the two amplitude
coefficients is at least 0.1uas.
The general formula for a quantity V is:
V = Sum_i)j=0,5 [(Sj)_i*t^j*sin(ARG) + Cj)_i*cos(ARG)]*t^j]
where, for X and Y:
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
and, for s+XY/2:
ARG = nl*l + nl'*l' + nF*F + nD*D + nOm*Om + nLV*LV + nLE*LE +npa*pa
l, l', F, D, Om, LMe, LV, LE, LMa, LJ, LS, LU, LN, pa being the
fundamental lunisolar and planetary arguments of the nutation theory.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
xp03.dat 76 1606 Terms in the series development for the quantity X,
based on the P03 precession (table1 of the paper)
yp03.dat 76 1281 Terms in the series development for the quantity Y,
based on the P03 precession (table2 of the paper)
sxy2p03.dat 55 72 *Terms in the series development for the quantity
s+XY/2, based on the P03 precession and IAU 2000A
nutation (table3 of the paper)
--------------------------------------------------------------------------------
Note on sxy2p03.dat: This table replaces the s+XY/2 table (file sxy2p03.dat)
provided at J/A+A/450/855 before 06-Nov-2006.
The two series are identical except that in the new one the constant term is
included and unused fundamental-argument coefficients are absent.
--------------------------------------------------------------------------------
See also:
J/A+A/355/398 : Celestial Ephemeris Origin definition (Capitaine+, 2000)
J/A+A/400/1145 : Celestial Intermediate Pole, Ephemeris Origin (Capitaine 2003)
J/A+A/450/855 : Methods for CIP and CIO localisation (Capitaine+, 2006)
Byte-by-byte Description of file: xp03.dat yp03.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- i Term number i
5- 6 I2 --- j Order of the Poisson term (power of t)
7- 18 F12.2 uas Sji (Sj)_i coefficient, in uas
19- 34 F16.4 uas Cji (Cj)_i coefficient, in uas
35- 37 I3 --- nl Mean anomaly of the Moon coefficient
38- 40 I3 --- nl' Mean anomaly of the Sun coefficient
41- 43 I3 --- nF L - Omega (L: Mean longitude of the Moon)
coefficient
44- 46 I3 --- nD Mean elongation from the Moon to the Sun
coefficient
47- 49 I3 --- nOm Mean longitude of the ascending node of
the Moon (Omega) coefficient
50- 52 I3 --- nLMe Mean longitude of Mercury coefficient
53- 55 I3 --- nLV Mean longitude of Venus coefficient
56- 58 I3 --- nLE Mean longitude of the Earth coefficient
59- 61 I3 --- nLMa Mean longitude of Mars coefficient
62- 64 I3 --- nLJ Mean longitude of Jupiter coefficient
65- 67 I3 --- nLS Mean longitude of Saturn coefficient
68- 70 I3 --- nLU Mean longitude of Uranus coefficient
71- 73 I3 --- nLN Mean longitude of Neptune coefficient
74- 76 I3 --- npa Accumulated general precession in
longitude coefficient
--------------------------------------------------------------------------------
Byte-by-byte Description of file: sxy2p03.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- i Term number i
3- 4 I2 --- j Order of the Poisson term (power of t)
5- 13 F9.2 uas Sji (Sj)_i coefficient, in uas
14- 23 F10.2 uas Cji (Cj)_i coefficient, in uas
24- 27 I4 --- nl Mean anomaly of the Moon coefficient
28- 31 I4 --- nl' Mean anomaly of the Sun coefficient
32- 35 I4 --- nF L - Omega (L: Mean longitude of the Moon)
coefficient
36- 39 I4 --- nD Mean elongation from the Moon to the Sun
coefficient
40- 43 I4 --- nOm Mean longitude of the ascending node of
the Moon (Omega) coefficient
44- 47 I4 --- nLV Mean longitude of Venus coefficient
48- 51 I4 --- nLE Mean longitude of the Earth coefficient
52- 55 I4 --- npa Accumulated general precession in
longitude coefficient
--------------------------------------------------------------------------------
Acknowledgements: Nicole Capitaine, n.capitaine(at)obspm.fr
References:
Capitaine et al., 2003A&A...412..567C 2003A&A...412..567C,
Expressions for IAU 2000 precession quantities
(End) Patricia Vannier [CDS] 06-Nov-2006