sofars/fundargs/fapa03.rs
1/// Fundamental argument, IERS Conventions (2003):
2/// general accumulated precession in longitude.
3///
4/// Status: canonical model.
5///
6/// Given:
7/// t f64 TDB, Julian centuries since J2000.0 (Note 1)
8///
9/// Returned (function value):
10/// f64 general precession in longitude, radians (Note 2)
11///
12/// Notes:
13///
14/// 1) Though t is strictly TDB, it is usually more convenient to use
15/// TT, which makes no significant difference.
16///
17/// 2) The expression used is as adopted in IERS Conventions (2003). It
18/// is taken from Kinoshita & Souchay (1990) and comes originally
19/// from Lieske et al. (1977).
20///
21/// References:
22///
23/// Kinoshita, H. and Souchay J. 1990, Celest.Mech. and Dyn.Astron.
24/// 48, 187
25///
26/// Lieske, J.H., Lederle, T., Fricke, W. & Morando, B. 1977,
27/// Astron.Astrophys. 58, 1-16
28///
29/// McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003),
30/// IERS Technical Note No. 32, BKG (2004)
31pub fn fapa03(t: f64) -> f64 {
32 /* General accumulated precession in longitude. */
33 (0.02438175 + 0.00000538691 * t) * t
34}