pmat06¶
-
erfa.
pmat06
(date1, date2)[source]¶ Wrapper for ERFA function
eraPmat06
.- Parameters
date1 : double array
date2 : double array
- Returns
rbp : double array
Notes
The ERFA documentation is below.
- - - - - - - - - - e r a P m a t 0 6 - - - - - - - - - - Precession matrix (including frame bias) from GCRS to a specified date, IAU 2006 model. Given: date1,date2 double TT as a 2-part Julian Date (Note 1) Returned: rbp double[3][3] bias-precession matrix (Note 2) 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 operates in the sense V(date) = rbp * V(GCRS), where the p-vector V(GCRS) is with respect to the Geocentric Celestial Reference System (IAU, 2000) and the p-vector V(date) is with respect to the mean equatorial triad of the given date. Called: eraPfw06 bias-precession F-W angles, IAU 2006 eraFw2m F-W angles to r-matrix References: Capitaine, N. & Wallace, P.T., 2006, Astron.Astrophys. 450, 855 Wallace, P.T. & Capitaine, N., 2006, Astron.Astrophys. 459, 981 Copyright (C) 2013-2019, NumFOCUS Foundation. Derived, with permission, from the SOFA library. See notes at end of file.