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Diffstat (limited to 'math/slalib/ge50.f')
| -rw-r--r-- | math/slalib/ge50.f | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/math/slalib/ge50.f b/math/slalib/ge50.f new file mode 100644 index 00000000..a6a8afeb --- /dev/null +++ b/math/slalib/ge50.f @@ -0,0 +1,108 @@ + SUBROUTINE slGE50 (DL, DB, DR, DD) +*+ +* - - - - - +* G E 5 0 +* - - - - - +* +* Transformation from IAU 1958 galactic coordinates to +* B1950.0 'FK4' equatorial coordinates (double precision) +* +* Given: +* DL,DB dp galactic longitude and latitude L2,B2 +* +* Returned: +* DR,DD dp B1950.0 'FK4' RA,Dec +* +* (all arguments are radians) +* +* Called: +* slDS2C, slDIMV, slDC2S, slADET, slDA2P, slDA1P +* +* Note: +* The equatorial coordinates are B1950.0 'FK4'. Use the +* routine slGAEQ if conversion to J2000.0 coordinates +* is required. +* +* Reference: +* Blaauw et al, Mon.Not.R.Astron.Soc.,121,123 (1960) +* +* P.T.Wallace Starlink 5 September 1993 +* +* 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 DL,DB,DR,DD + + DOUBLE PRECISION slDA2P,slDA1P + + DOUBLE PRECISION V1(3),V2(3),R,D,RE,DE + +* +* L2,B2 system of galactic coordinates +* +* P = 192.25 RA of galactic north pole (mean B1950.0) +* Q = 62.6 inclination of galactic to mean B1950.0 equator +* R = 33 longitude of ascending node +* +* P,Q,R are degrees +* +* +* Equatorial to galactic rotation matrix +* +* The Euler angles are P, Q, 90-R, about the z then y then +* z axes. +* +* +CP.CQ.SR-SP.CR +SP.CQ.SR+CP.CR -SQ.SR +* +* -CP.CQ.CR-SP.SR -SP.CQ.CR+CP.SR +SQ.CR +* +* +CP.SQ +SP.SQ +CQ +* + + DOUBLE PRECISION RMAT(3,3) + DATA RMAT(1,1),RMAT(1,2),RMAT(1,3), + : RMAT(2,1),RMAT(2,2),RMAT(2,3), + : RMAT(3,1),RMAT(3,2),RMAT(3,3) / + : -0.066988739415D0,-0.872755765852D0,-0.483538914632D0, + : +0.492728466075D0,-0.450346958020D0,+0.744584633283D0, + : -0.867600811151D0,-0.188374601723D0,+0.460199784784D0 / + + + +* Spherical to Cartesian + CALL slDS2C(DL,DB,V1) + +* Rotate to mean B1950.0 + CALL slDIMV(RMAT,V1,V2) + +* Cartesian to spherical + CALL slDC2S(V2,R,D) + +* Introduce E-terms + CALL slADET(R,D,1950D0,RE,DE) + +* Express in conventional ranges + DR=slDA2P(RE) + DD=slDA1P(DE) + + END |