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authorJoe Hunkeler <jhunkeler@gmail.com>2015-08-11 16:51:37 -0400
committerJoe Hunkeler <jhunkeler@gmail.com>2015-08-11 16:51:37 -0400
commit40e5a5811c6ffce9b0974e93cdd927cbcf60c157 (patch)
tree4464880c571602d54f6ae114729bf62a89518057 /math/slalib/hfk5z.f
downloadiraf-osx-40e5a5811c6ffce9b0974e93cdd927cbcf60c157.tar.gz
Repatch (from linux) of OSX IRAF
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+ SUBROUTINE slHF5Z (RH,DH,EPOCH,R5,D5,DR5,DD5)
+*+
+* - - - - - -
+* H F 5 Z
+* - - - - - -
+*
+* Transform a Hipparcos star position into FK5 J2000, assuming
+* zero Hipparcos proper motion.
+*
+* (double precision)
+*
+* Given:
+* RH d Hipparcos RA (radians)
+* DH d Hipparcos Dec (radians)
+* EPOCH d Julian epoch (TDB)
+*
+* Returned (all FK5, equinox J2000, epoch EPOCH):
+* R5 d RA (radians)
+* D5 d Dec (radians)
+*
+* Called: slDS2C, slDAVM, slDMXV, slDMXM,
+* slDIMV, slDVXV, slDC6S, slDA2P
+*
+* Notes:
+*
+* 1) The proper motion in RA is dRA/dt rather than cos(Dec)*dRA/dt.
+*
+* 2) The FK5 to Hipparcos transformation consists of a pure
+* rotation and spin; zonal errors in the FK5 catalogue are
+* not taken into account.
+*
+* 3) The published orientation and spin components are interpreted
+* as "axial vectors". An axial vector points at the pole of the
+* rotation and its length is the amount of rotation in radians.
+*
+* 4) It was the intention that Hipparcos should be a close
+* approximation to an inertial frame, so that distant objects
+* have zero proper motion; such objects have (in general)
+* non-zero proper motion in FK5, and this routine returns those
+* fictitious proper motions.
+*
+* 5) The position returned by this routine is in the FK5 J2000
+* reference frame but at Julian epoch EPOCH.
+*
+* 6) See also slFK5H, slHFK5, sla_FK5ZHZ.
+*
+* Reference:
+*
+* M.Feissel & F.Mignard, Astron. Astrophys. 331, L33-L36 (1998).
+*
+* P.T.Wallace Starlink 30 December 1999
+*
+* Copyright (C) 1999 Rutherford Appleton Laboratory
+*
+* License:
+* This program is free software; you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation; either version 2 of the License, or
+* (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program (see SLA_CONDITIONS); if not, write to the
+* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+* Boston, MA 02110-1301 USA
+*
+* Copyright (C) 1995 Association of Universities for Research in Astronomy Inc.
+*-
+
+ IMPLICIT NONE
+
+ DOUBLE PRECISION RH,DH,EPOCH,R5,D5,DR5,DD5
+
+ DOUBLE PRECISION AS2R
+ PARAMETER (AS2R=0.484813681109535994D-5)
+
+* FK5 to Hipparcos orientation and spin (radians, radians/year)
+ DOUBLE PRECISION EPX,EPY,EPZ
+ DOUBLE PRECISION OMX,OMY,OMZ
+
+ PARAMETER ( EPX = -19.9D-3 * AS2R,
+ : EPY = -9.1D-3 * AS2R,
+ : EPZ = +22.9D-3 * AS2R )
+
+ PARAMETER ( OMX = -0.30D-3 * AS2R,
+ : OMY = +0.60D-3 * AS2R,
+ : OMZ = +0.70D-3 * AS2R )
+
+ DOUBLE PRECISION PH(3),ORTN(3),R5H(3,3),S5(3),SH(3),T,VST(3),
+ : RST(3,3),R5HT(3,3),PV5E(6),VV(3),W,R,V
+
+ DOUBLE PRECISION slDA2P
+
+
+
+* Hipparcos barycentric position vector (normalized).
+ CALL slDS2C(RH,DH,PH)
+
+* FK5 to Hipparcos orientation matrix.
+ ORTN(1) = EPX
+ ORTN(2) = EPY
+ ORTN(3) = EPZ
+ CALL slDAVM(ORTN,R5H)
+
+* Hipparcos wrt FK5 spin vector.
+ S5(1) = OMX
+ S5(2) = OMY
+ S5(3) = OMZ
+
+* Rotate the spin vector into the Hipparcos frame.
+ CALL slDMXV(R5H,S5,SH)
+
+* Time interval from J2000 to epoch.
+ T = EPOCH-2000D0
+
+* Axial vector: accumulated Hipparcos wrt FK5 spin over that interval.
+ VST(1) = OMX*T
+ VST(2) = OMY*T
+ VST(3) = OMZ*T
+
+* Express the accumulated spin as a rotation matrix.
+ CALL slDAVM(VST,RST)
+
+* Rotation matrix: accumulated spin, then FK5 to Hipparcos.
+ CALL slDMXM(R5H,RST,R5HT)
+
+* De-orient & de-spin the vector into FK5 J2000 at epoch.
+ CALL slDIMV(R5HT,PH,PV5E)
+ CALL slDVXV(SH,PH,VV)
+ CALL slDIMV(R5HT,VV,PV5E(4))
+
+* FK5 position/velocity 6-vector to spherical.
+ CALL slDC6S(PV5E,W,D5,R,DR5,DD5,V)
+ R5 = slDA2P(W)
+
+ END