C2TCIO Subroutine

  1. astro_module.f90
  2. astro_module
  3. C2TCIO

public subroutine C2TCIO(rc2i, era, rpom, rc2t)

Assemble the celestial to terrestrial matrix from CIO-based components (the celestial-to-intermediate matrix, the Earth Rotation Angle and the polar motion matrix).

Status: support routine.

Notes

  1. This routine constructs the rotation matrix that transforms vectors in the celestial system into vectors in the terrestrial system. It does so starting from precomputed components, namely the matrix which rotates from celestial coordinates to the intermediate frame, the Earth rotation angle and the polar motion matrix. One use of the present routine is when generating a series of celestial-to-terrestrial matrices where only the Earth Rotation Angle changes, avoiding the considerable overhead of recomputing the precession-nutation more often than necessary to achieve given accuracy objectives.

  2. The relationship between the arguments is as follows:

    [TRS]  =  RPOM * R_3(ERA) * RC2I * [CRS]

       =  RC2T * [CRS]

    where [CRS] is a vector in the Geocentric Celestial Reference System and [TRS] is a vector in the International Terrestrial Reference System (see IERS Conventions 2003).

Reference

  • McCarthy, D. D., Petit, G. (eds.), 2004, IERS Conventions (2003), IERS Technical Note No. 32, BKG

History

  • IAU SOFA revision: 2013 August 24

Arguments

TypeIntentOptionalAttributesName
real(kind=wp), intent(in), dimension(3,3):: rc2i

celestial-to-intermediate matrix
real(kind=wp), intent(in) :: era

Earth rotation angle (radians)
real(kind=wp), intent(in), dimension(3,3):: rpom

polar-motion matrix
real(kind=wp), intent(out), dimension(3,3):: rc2t

celestial-to-terrestrial matrix

Calls

proc~~c2tcio~~CallsGraph proc~c2tcio C2TCIO proc~rz RZ proc~c2tcio->proc~rz proc~rxr RXR proc~c2tcio->proc~rxr

Called by

proc~~c2tcio~~CalledByGraph proc~c2tcio C2TCIO proc~c2t00a C2T00A proc~c2t00a->proc~c2tcio proc~c2txy C2TXY proc~c2txy->proc~c2tcio proc~c2tceo C2TCEO proc~c2tceo->proc~c2tcio proc~c2t06a C2T06A proc~c2t06a->proc~c2tcio proc~c2t00b C2T00B proc~c2t00b->proc~c2tcio

Contents

Source Code

C2TCIO

Source Code

    subroutine C2TCIO ( rc2i, era, rpom, rc2t )

    implicit none

    real(wp),dimension(3,3),intent(in) :: rc2i !! celestial-to-intermediate matrix
    real(wp),intent(in) :: era !! Earth rotation angle (radians)
    real(wp),dimension(3,3),intent(in) :: rpom !! polar-motion matrix
    real(wp),dimension(3,3),intent(out) :: rc2t !! celestial-to-terrestrial matrix

    real(wp) :: r(3,3)

    !  Construct the matrix.
    call CR ( rc2i, r )
    call RZ ( era, r )
    call RXR ( rpom, r, rc2t )

    end subroutine C2TCIO