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authorJoseph Hunkeler <jhunkeler@gmail.com>2015-07-08 20:46:52 -0400
committerJoseph Hunkeler <jhunkeler@gmail.com>2015-07-08 20:46:52 -0400
commitfa080de7afc95aa1c19a6e6fc0e0708ced2eadc4 (patch)
treebdda434976bc09c864f2e4fa6f16ba1952b1e555 /math/slalib/subet.f
downloadiraf-linux-fa080de7afc95aa1c19a6e6fc0e0708ced2eadc4.tar.gz
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+ SUBROUTINE slSUET (RC, DC, EQ, RM, DM)
+*+
+* - - - - - -
+* S U E T
+* - - - - - -
+*
+* Remove the E-terms (elliptic component of annual aberration)
+* from a pre IAU 1976 catalogue RA,Dec to give a mean place
+* (double precision)
+*
+* Given:
+* RC,DC dp RA,Dec (radians) with E-terms included
+* EQ dp Besselian epoch of mean equator and equinox
+*
+* Returned:
+* RM,DM dp RA,Dec (radians) without E-terms
+*
+* Called:
+* slETRM, slDS2C, sla_,DVDV, slDC2S, slDA2P
+*
+* Explanation:
+* Most star positions from pre-1984 optical catalogues (or
+* derived from astrometry using such stars) embody the
+* E-terms. This routine converts such a position to a
+* formal mean place (allowing, for example, comparison with a
+* pulsar timing position).
+*
+* Reference:
+* Explanatory Supplement to the Astronomical Ephemeris,
+* section 2D, page 48.
+*
+* P.T.Wallace Starlink 10 May 1990
+*
+* Copyright (C) 1995 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 RC,DC,EQ,RM,DM
+
+ DOUBLE PRECISION slDA2P,slDVDV
+ DOUBLE PRECISION A(3),V(3),F
+
+ INTEGER I
+
+
+
+* E-terms
+ CALL slETRM(EQ,A)
+
+* Spherical to Cartesian
+ CALL slDS2C(RC,DC,V)
+
+* Include the E-terms
+ F=1D0+slDVDV(V,A)
+ DO I=1,3
+ V(I)=F*V(I)-A(I)
+ END DO
+
+* Cartesian to spherical
+ CALL slDC2S(V,RM,DM)
+
+* Bring RA into conventional range
+ RM=slDA2P(RM)
+
+ END