PMAT00 Subroutine

  1. astro_module.f90
  2. astro_module
  3. PMAT00

public subroutine PMAT00(date1, date2, rbp)

Precession matrix (including frame bias) from GCRS to a specified date, IAU 2000 model.

Status: support routine.

Notes

  1. The TT date DATE1+DATE2 is a Julian Date, apportioned in any convenient way between the arguments DATE1 and DATE2. For example, JD(TT)=2450123.7 could be expressed in any of these ways, among others:

        DATE1          DATE2

 2450123.7D0        0D0        (JD method)
  2451545D0      -1421.3D0     (J2000 method)
 2400000.5D0     50123.2D0     (MJD method)
 2450123.5D0       0.2D0       (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.

Reference

  • IAU: Trans. International Astronomical Union, Vol. XXIVB; Proc. 24th General Assembly, Manchester, UK. Resolutions B1.3, B1.6. (2000)

History

  • IAU SOFA revision: 2009 December 21

Arguments

TypeIntentOptionalAttributesName
real(kind=wp), intent(in) :: date1

TT as a 2-part Julian Date (Note 1)
real(kind=wp), intent(in) :: date2

TT as a 2-part Julian Date (Note 1)
real(kind=wp), intent(out), dimension(3,3):: rbp

bias-precession matrix (Note 2)

Calls

proc~~pmat00~~CallsGraph proc~pmat00 PMAT00 proc~bp00 BP00 proc~pmat00->proc~bp00 proc~ry RY proc~bp00->proc~ry proc~rx RX proc~bp00->proc~rx proc~ir IR proc~bp00->proc~ir proc~pr00 PR00 proc~bp00->proc~pr00 proc~bi00 BI00 proc~bp00->proc~bi00 proc~rz RZ proc~bp00->proc~rz proc~rxr RXR proc~bp00->proc~rxr

Contents

Source Code

PMAT00

Source Code

    subroutine PMAT00 ( date1, date2, rbp )

    implicit none

    real(wp),intent(in) :: date1 !! TT as a 2-part Julian Date (Note 1)
    real(wp),intent(in) :: date2 !! TT as a 2-part Julian Date (Note 1)
    real(wp),dimension(3,3),intent(out) :: rbp !! bias-precession matrix (Note 2)

    real(wp) :: rb(3,3), rp(3,3)

    !  Obtain the required matrix (discarding others).
    call BP00 ( date1, date2, rb, rp, rbp )

    end subroutine PMAT00