FK5HIP Subroutine

  1. astro_module.f90
  2. astro_module
  3. FK5HIP

public subroutine FK5HIP(r5h, s5h)

FK5 to Hipparcos rotation and spin.

Status: support routine.

Notes

  1. This routine models the FK5 to Hipparcos transformation as a pure rotation and spin; zonal errors in the FK5 catalogue are not taken into account.

  2. The r-matrix R5H operates in the sense:

       P_Hipparcos = R5H x P_FK5

    where P_FK5 is a p-vector in the FK5 frame, and P_Hipparcos is the equivalent Hipparcos p-vector.

  3. The r-vector S5H represents the time derivative of the FK5 to Hipparcos rotation. The units are radians per year (Julian, TDB).

Reference

  • F. Mignard & M. Froeschle, Astron.Astrophys., 354, 732-739 (2000).

History

  • IAU SOFA revision: 2017 October 12

Arguments

TypeIntentOptionalAttributesName
real(kind=wp), intent(out), dimension(3,3):: r5h

r-matrix: FK5 rotation wrt Hipparcos (Note 2)
real(kind=wp), intent(out), dimension(3):: s5h

Calls

proc~~fk5hip~~CallsGraph proc~fk5hip FK5HIP proc~rv2m RV2M proc~fk5hip->proc~rv2m

Called by

proc~~fk5hip~~CalledByGraph proc~fk5hip FK5HIP proc~fk52h FK52H proc~fk52h->proc~fk5hip proc~hfk5z HFK5Z proc~hfk5z->proc~fk5hip proc~fk5hz FK5HZ proc~fk5hz->proc~fk5hip proc~h2fk5 H2FK5 proc~h2fk5->proc~fk5hip

Contents

Source Code

FK5HIP

Source Code

    subroutine FK5HIP ( r5h, s5h )

    implicit none

    real(wp),dimension(3,3),intent(out) :: r5h !! r-matrix: FK5 rotation wrt Hipparcos (Note 2)
    real(wp),dimension(3),intent(out) :: s5h !! r-vector: FK5 spin wrt Hipparcos (Note 3)

    !  FK5 to Hipparcos orientation and spin (radians, radians/year)
    real(wp),parameter :: epx = -19.9e-3_wp * das2r
    real(wp),parameter :: epy =  -9.1e-3_wp * das2r
    real(wp),parameter :: epz = +22.9e-3_wp * das2r
    real(wp),parameter :: omx = -0.30e-3_wp * das2r
    real(wp),parameter :: omy = +0.60e-3_wp * das2r
    real(wp),parameter :: omz = +0.70e-3_wp * das2r

    real(wp) :: v(3)

    !  FK5 to Hipparcos orientation expressed as an r-vector.
    v(1) = epx
    v(2) = epy
    v(3) = epz

    !  Re-express as an r-matrix.
    call RV2M ( v, r5h )

    !  Hipparcos wrt FK5 spin expressed as an r-vector.
    s5h(1) = omx
    s5h(2) = omy
    s5h(3) = omz

    end subroutine FK5HIP