nutation.h File Reference

Typedefs
typedef int(*	novas_nutation_provider) (double jd_tt_high, double jd_tt_low, double *restrict dpsi, double *restrict deps)

Functions
int	iau2000a (double jd_tt_high, double jd_tt_low, double *restrict dpsi, double *restrict deps)
int	iau2000b (double jd_tt_high, double jd_tt_low, double *restrict dpsi, double *restrict deps)
int	nu2000k (double jd_tt_high, double jd_tt_low, double *restrict dpsi, double *restrict deps)

Detailed Description

Author

G. Kaplan and A. Kovacs

SuperNOVAS prototypes for the IAU2000 nutation series calculations, with varying trade-offs between computational cost and precision. It provides support for both the IAU 2000A and IAU 2000B series as well as a NOVAS-specific truncated low-precision version we call NU2000K.

Based on the NOVAS C Edition, Version 3.1:

U. S. Naval Observatory
Astronomical Applications Dept.
Washington, DC
http://www.usno.navy.mil/USNO/astronomical-applications

Typedef Documentation

novas_nutation_provider

typedef int(* novas_nutation_provider) (double jd_tt_high, double jd_tt_low, double *restrict dpsi, double *restrict deps)

Function type definition for the IAU 2000 nutation series calculation.

Parameters

	jd_tt_high	[day] High-order part of the Terrestrial Time (TT) based Julian date. Typically it may be the integer part of a split date for the highest precision, or the full date for normal (reduced) precision.
	jd_tt_low	[day] Low-order part of the Terrestrial Time (TT) based Julian date. Typically it may be the fractional part of a split date for the highest precision, or 0.0 for normal (reduced) precision.
[out]	dpsi	[rad] δψ Nutation (luni-solar + planetary) in longitude, in radians.
[out]	deps	[rad] δε Nutation (luni-solar + planetary) in obliquity, in radians.

Returns

0 if successful, or else -1 (errno should be set to indicate the type of error).

See also

nutation_angles()

iau2000a()

iau2000b()

iau2000k()

Author

Attila Kovacs

Since

1.0

Function Documentation

iau2000a()

int iau2000a	(	double	jd_tt_high,
		double	jd_tt_low,
		double *restrict	dpsi,
		double *restrict	deps
	)

Computes the IAU 2000A nutation high-precision series for the specified date. It is rather expensive computationally.

The IAU 2000A nutation model is MHB_2000 without the free core nutation and without the corrections to Lieske precession.

REFERENCES:

1. IERS Conventions (2003), Chapter 5.
2. Simon et al. (1994) Astronomy and Astrophysics 282, 663-683, esp. Sections 3.4-3.5.

Parameters

	jd_tt_high	[day] High-order part of the Terrestrial Time (TT) based Julian date. Typically it may be the integer part of a split date for the highest precision, or the full date for normal (reduced) precision.
	jd_tt_low	[day] Low-order part of the Terrestrial Time (TT) based Julian date. Typically it may be the fractional part of a split date for the highest precision, or 0.0 for normal (reduced) precision.
[out]	dpsi	[rad] δψ Nutation (luni-solar + planetary) in longitude, in radians. It may be NULL if not required.
[out]	deps	[rad] δε Nutation (luni-solar + planetary) in obliquity, in radians. It may be NULL if not required.

Returns

0

See also

iau2000b()

nu2000k()

nutation_angles()

novas_nutation_provider

References accum_prec(), ASEC2RAD, novas_delaunay_args::D, novas_delaunay_args::F, fund_args(), novas_delaunay_args::l, novas_delaunay_args::l1, NOVAS_EARTH, NOVAS_JUPITER, NOVAS_MARS, NOVAS_MERCURY, NOVAS_NEPTUNE, NOVAS_SATURN, NOVAS_URANUS, NOVAS_VENUS, novas_delaunay_args::Omega, and planet_lon().

iau2000b()

int iau2000b	(	double	jd_tt_high,
		double	jd_tt_low,
		double *restrict	dpsi,
		double *restrict	deps
	)

Compute the forced nutation of the non-rigid Earth based on the IAU 2000B precession / nutation model.

IAU 2000B reproduces the IAU 2000A model to a precision of 1 milliarcsecond in the interval 1995-2020.

REFERENCES:

1. McCarthy, D. and Luzum, B. (2003). "An Abridged Model of the Precession & Nutation of the Celestial Pole," Celestial Mechanics and Dynamical Astronomy, Volume 85, Issue 1, Jan. 2003, p. 37. (IAU 2000B) IERS Conventions (2003), Chapter 5.

Parameters

	jd_tt_high	[day] High-order part of the Terrestrial Time (TT) based Julian date. Typically it may be the integer part of a split date for the highest precision, or the full date for normal (reduced) precision.
	jd_tt_low	[day] Low-order part of the Terrestrial Time (TT) based Julian date. Typically it may be the fractional part of a split date for the highest precision, or 0.0 for normal (reduced) precision.
[out]	dpsi	[rad] δψ Nutation (luni-solar + planetary) in longitude, in radians. It may be NULL if not required.
[out]	deps	[rad] δε Nutation (luni-solar + planetary) in obliquity, in radians. It may be NULL if not required.

Returns

0

See also

iau2000a()

nu2000k()

set_nutation_lp_provider()

nutation_angles()

References novas_delaunay_args::D, novas_delaunay_args::F, fund_args(), novas_delaunay_args::l, novas_delaunay_args::l1, and novas_delaunay_args::Omega.

nu2000k()

int nu2000k	(	double	jd_tt_high,
		double	jd_tt_low,
		double *restrict	dpsi,
		double *restrict	deps
	)

Computes the forced nutation of the non-rigid Earth: Model NU2000K. This model is a modified version of IAU 2000A, which has been truncated for speed of execution, and uses Simon et al. (1994) fundamental arguments throughout. NU2000K agrees with IAU 2000A at the 0.1 milliarcsecond level from 1700 to 2300. It has the most modest computational cost among the implementations provided in the NOVAS library.

NU2000K was compared to IAU 2000A over six centuries (1700-2300). The average error in dψ is 20 microarcseconds, with 98% of the errors < 60 microarcseconds; the average error in dεis 8 microarcseconds, with 100% of the errors < 60 microarcseconds.

NU2000K was developed by G. Kaplan (USNO) in March 2004

REFERENCES:

1. IERS Conventions (2003), Chapter 5.
2. Simon et al. (1994) Astronomy and Astrophysics 282, 663-683, esp. Sections 3.4-3.5.

Parameters

	jd_tt_high	[day] High-order part of the Terrestrial Time (TT) based Julian date. Typically it may be the integer part of a split date for the highest precision, or the full date for normal (reduced) precision.
	jd_tt_low	[day] Low-order part of the Terrestrial Time (TT) based Julian date. Typically it may be the fractional part of a split date for the highest precision, or 0.0 for normal (reduced) precision.
[out]	dpsi	[rad] δψ Nutation (luni-solar + planetary) in longitude, in radians. It may be NULL if not required.
[out]	deps	[rad] δε Nutation (luni-solar + planetary) in obliquity, in radians. It may be NULL if not required.

Returns

0

See also

iau2000a()

iau2000b()

nutation_angles()

novas_nutation_provider

References accum_prec(), novas_delaunay_args::D, novas_delaunay_args::F, fund_args(), novas_delaunay_args::l, novas_delaunay_args::l1, NOVAS_EARTH, NOVAS_JUPITER, NOVAS_MARS, NOVAS_SATURN, NOVAS_VENUS, novas_delaunay_args::Omega, and planet_lon().