PNM00B Subroutine

  1. astro_module.f90
  2. astro_module
  3. PNM00B

public subroutine PNM00B(date1, date2, rbpn)

Form the matrix of precession-nutation for a given date (including frame bias), equinox-based, IAU 2000B model.

Status: support routine.

Notes

  1. The TT date DATE1+DATE2 is a Julian Date, apportioned in any convenient way between the two arguments. 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) = RBPN * V(GCRS), where the p-vector V(date) is with respect to the true equatorial triad of date DATE1+DATE2 and the p-vector V(GCRS) is with respect to the Geocentric Celestial Reference System (IAU, 2000).

  3. The present routine is faster, but slightly less accurate (about 1 mas), than the PNM00A routine.

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):: rbpn

bias-precession-nutation matrix (Note 2)

Calls

proc~~pnm00b~~CallsGraph proc~pnm00b PNM00B proc~pn00b PN00B proc~pnm00b->proc~pn00b proc~nut00b NUT00B proc~pn00b->proc~nut00b proc~pn00 PN00 proc~pn00b->proc~pn00 proc~obl80 OBL80 proc~pn00->proc~obl80 proc~numat NUMAT proc~pn00->proc~numat proc~bp00 BP00 proc~pn00->proc~bp00 proc~rxr RXR proc~pn00->proc~rxr proc~pr00 PR00 proc~pn00->proc~pr00 proc~rx RX proc~numat->proc~rx proc~ir IR proc~numat->proc~ir proc~rz RZ proc~numat->proc~rz proc~bp00->proc~rxr proc~bp00->proc~pr00 proc~bp00->proc~rx proc~ry RY proc~bp00->proc~ry proc~bp00->proc~ir proc~bp00->proc~rz proc~bi00 BI00 proc~bp00->proc~bi00

Called by

proc~~pnm00b~~CalledByGraph proc~pnm00b PNM00B proc~s00b S00B proc~s00b->proc~pnm00b proc~c2i00b C2I00B proc~c2i00b->proc~pnm00b proc~xys00b XYS00B proc~xys00b->proc~pnm00b proc~c2t00b C2T00B proc~c2t00b->proc~c2i00b

Contents

Source Code

PNM00B

Source Code

    subroutine PNM00B ( date1, date2, rbpn )

    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) :: rbpn !! bias-precession-nutation matrix (Note 2)

    real(wp) ::  dpsi, deps, epsa, &
                 rb(3,3), rp(3,3), rbp(3,3), rn(3,3)

    !  Obtain the required matrix (discarding other results).
    call PN00B ( date1, date2, &
                 dpsi, deps, epsa, rb, rp, rbp, rn, rbpn )

    end subroutine PNM00B