NUMAT Subroutine

  1. astro_module.f90
  2. astro_module
  3. NUMAT

public subroutine NUMAT(epsa, dpsi, deps, rmatn)

Form the matrix of nutation.

Status: support routine.

Notes

  1. The supplied mean obliquity EPSA, must be consistent with the precession-nutation models from which DPSI and DEPS were obtained.

  2. The caller is responsible for providing the nutation components; they are in longitude and obliquity, in radians and are with respect to the equinox and ecliptic of date.

  3. The matrix operates in the sense V(true) = RMATN * V(mean), where the p-vector V(true) is with respect to the true equatorial triad of date and the p-vector V(mean) is with respect to the mean equatorial triad of date.

Reference

  • Explanatory Supplement to the Astronomical Almanac, P. Kenneth Seidelmann (ed), University Science Books (1992), Section 3.222-3 (p114).

History

  • IAU SOFA revision: 2006 November 13

Arguments

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

mean obliquity of date (Note 1)
real(kind=wp), intent(in) :: dpsi

nutation (Note 2)
real(kind=wp), intent(in) :: deps

nutation (Note 2)
real(kind=wp), intent(out), dimension(3,3):: rmatn

nutation matrix (Note 3)

Calls

proc~~numat~~CallsGraph proc~numat NUMAT proc~ir IR proc~numat->proc~ir proc~rz RZ proc~numat->proc~rz proc~rx RX proc~numat->proc~rx

Called by

proc~~numat~~CalledByGraph proc~numat NUMAT proc~pn00 PN00 proc~pn00->proc~numat proc~num06a NUM06A proc~num06a->proc~numat proc~nutm80 NUTM80 proc~nutm80->proc~numat proc~pn00a PN00A proc~pn00a->proc~pn00 proc~pnm80 PNM80 proc~pnm80->proc~nutm80 proc~pn00b PN00B proc~pn00b->proc~pn00 proc~c2tpe C2TPE proc~c2tpe->proc~pn00 proc~pnm00a PNM00A proc~pnm00a->proc~pn00a proc~num00a NUM00A proc~num00a->proc~pn00a proc~num00b NUM00B proc~num00b->proc~pn00b proc~pnm00b PNM00B proc~pnm00b->proc~pn00b proc~xys00a XYS00A proc~xys00a->proc~pnm00a proc~s00a S00A proc~s00a->proc~pnm00a proc~c2i00b C2I00B proc~c2i00b->proc~pnm00b proc~c2i00a C2I00A proc~c2i00a->proc~pnm00a proc~s00b S00B proc~s00b->proc~pnm00b proc~xys00b XYS00B proc~xys00b->proc~pnm00b proc~c2t00b C2T00B proc~c2t00b->proc~c2i00b proc~c2t00a C2T00A proc~c2t00a->proc~c2i00a

Contents

Source Code

NUMAT

Source Code

    subroutine NUMAT ( epsa, dpsi, deps, rmatn )

    implicit none

    real(wp),intent(in) :: epsa !! mean obliquity of date (Note 1)
    real(wp),intent(in) :: dpsi !! nutation (Note 2)
    real(wp),intent(in) :: deps !! nutation (Note 2)
    real(wp),dimension(3,3),intent(out) :: rmatn !! nutation matrix (Note 3)

    !  Build the rotation matrix.
    call IR ( rmatn )
    call RX ( epsa, rmatn )
    call RZ ( -dpsi, rmatn )
    call RX ( -(epsa+deps), rmatn )

    end subroutine NUMAT