PMAT06 Subroutine

  1. astro_module.f90
  2. astro_module
  3. PMAT06

public subroutine PMAT06(date1, date2, rbp)

Precession matrix (including frame bias) from GCRS to a specified date, IAU 2006 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.

References

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

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

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~~pmat06~~CallsGraph proc~pmat06 PMAT06 proc~pfw06 PFW06 proc~pmat06->proc~pfw06 proc~fw2m FW2M proc~pmat06->proc~fw2m proc~obl06 OBL06 proc~pfw06->proc~obl06 proc~ir IR proc~fw2m->proc~ir proc~rz RZ proc~fw2m->proc~rz proc~rx RX proc~fw2m->proc~rx

Called by

proc~~pmat06~~CalledByGraph proc~pmat06 PMAT06 proc~bp06 BP06 proc~bp06->proc~pmat06 proc~pb06 PB06 proc~pb06->proc~pmat06 proc~ecm06 ECM06 proc~ecm06->proc~pmat06 proc~eceq06 ECEQ06 proc~eceq06->proc~ecm06 proc~eqec06 EQEC06 proc~eqec06->proc~ecm06

Contents

Source Code

PMAT06

Source Code

    subroutine PMAT06 ( 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) :: gamb, phib, psib, epsa

    !  Bias-precession Fukushima-Williams angles.
    call PFW06 ( date1, date2, gamb, phib, psib, epsa )

    !  Form the matrix.
    call FW2M ( gamb, phib, psib, epsa, rbp )

    end subroutine PMAT06