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bp06

sofars::pnp

Function bp06 

Source 
pub fn bp06(
    date1: f64,
    date2: f64,
) -> ([[f64; 3]; 3], [[f64; 3]; 3], [[f64; 3]; 3])
Expand description

Frame bias and precession, IAU 2006.

Given: date1,date2 f64 TT as a 2-part Julian Date (Note 1)

Returned (function value): (rb, rp, rbp) ([[f64; 3]; 3], [[f64; 3]; 3], [[f64; 3]; 3])

rb frame bias matrix (Note 2) rp precession matrix (Note 3) rbp bias-precession matrix (Note 4)

Notes:

  1. The TT date date1+date2 is a Julian Date, apportioned in any convenient way between the two arguments. For example, JD(TT)=2450123.7 could be expressed in any of these ways, among others:

        date1         date2

2450123.7           0.0       (JD method)
2451545.0       -1421.3       (J2000 method)
2400000.5       50123.2       (MJD method)
2450123.5           0.2       (date & time method)

    The JD method is the most natural and convenient to use in cases where the loss of several decimal digits of resolution is acceptable. The J2000 method is best matched to the way the argument is handled internally and will deliver the optimum resolution. The MJD method and the date & time methods are both good compromises between resolution and convenience.

  2. The matrix rb transforms vectors from GCRS to mean J2000.0 by applying frame bias.

  3. The matrix rp transforms vectors from mean J2000.0 to mean of date by applying precession.

  4. The matrix rbp transforms vectors from GCRS to mean of date by applying frame bias then precession. It is the product rp x rb.

Called: iauPfw06 bias-precession F-W angles, IAU 2006 iauFw2m F-W angles to r-matrix iauPmat06 PB matrix, IAU 2006 iauTr transpose r-matrix iauRxr product of two r-matrices iauCr copy r-matrix

References:

Capitaine, N. & Wallace, P.T., 2006, Astron.Astrophys. 450, 855

Wallace, P.T. & Capitaine, N., 2006, Astron.Astrophys. 459, 981