source: trunk/FACT++/pal/palGalsup.c@ 19926

Last change on this file since 19926 was 18347, checked in by tbretz, 9 years ago
File size: 3.1 KB
Line 
1/*
2*+
3* Name:
4* palGalsup
5
6* Purpose:
7* Convert from galactic to supergalactic coordinates
8
9* Language:
10* Starlink ANSI C
11
12* Type of Module:
13* Library routine
14
15* Invocation:
16* void palGalsup ( double dl, double db, double *dsl, double *dsb );
17
18* Arguments:
19* dl = double (Given)
20* Galactic longitude.
21* db = double (Given)
22* Galactic latitude.
23* dsl = double * (Returned)
24* Supergalactic longitude.
25* dsb = double * (Returned)
26* Supergalactic latitude.
27
28* Description:
29* Transformation from IAU 1958 galactic coordinates to
30* de Vaucouleurs supergalactic coordinates.
31
32* Authors:
33* PTW: Pat Wallace (STFC)
34* TIMJ: Tim Jenness (JAC, Hawaii)
35* {enter_new_authors_here}
36
37* See Also:
38* - de Vaucouleurs, de Vaucouleurs, & Corwin, Second Reference
39* Catalogue of Bright Galaxies, U. Texas, page 8.
40* - Systems & Applied Sciences Corp., Documentation for the
41* machine-readable version of the above catalogue,
42* Contract NAS 5-26490.
43*
44* (These two references give different values for the galactic
45* longitude of the supergalactic origin. Both are wrong; the
46* correct value is L2=137.37.)
47
48* History:
49* 2012-02-12(TIMJ):
50* Initial version with documentation taken from Fortran SLA
51* Adapted with permission from the Fortran SLALIB library.
52* {enter_further_changes_here}
53
54* Copyright:
55* Copyright (C) 1999 Rutherford Appleton Laboratory
56* Copyright (C) 2012 Science and Technology Facilities Council.
57* All Rights Reserved.
58
59* Licence:
60* This program is free software: you can redistribute it and/or
61* modify it under the terms of the GNU Lesser General Public
62* License as published by the Free Software Foundation, either
63* version 3 of the License, or (at your option) any later
64* version.
65*
66* This program is distributed in the hope that it will be useful,
67* but WITHOUT ANY WARRANTY; without even the implied warranty of
68* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
69* GNU Lesser General Public License for more details.
70*
71* You should have received a copy of the GNU Lesser General
72* License along with this program. If not, see
73* <http://www.gnu.org/licenses/>.
74
75* Bugs:
76* {note_any_bugs_here}
77*-
78*/
79
80#include "pal.h"
81#include "pal1sofa.h"
82
83void palGalsup ( double dl, double db, double *dsl, double *dsb ) {
84
85 double v1[3];
86 double v2[3];
87
88/*
89* System of supergalactic coordinates:
90*
91* SGL SGB L2 B2 (deg)
92* - +90 47.37 +6.32
93* 0 0 - 0
94*
95* Galactic to supergalactic rotation matrix:
96*/
97 double rmat[3][3] = {
98 { -0.735742574804,+0.677261296414,+0.000000000000 },
99 { -0.074553778365,-0.080991471307,+0.993922590400 },
100 { +0.673145302109,+0.731271165817,+0.110081262225 }
101 };
102
103 /* Spherical to Cartesian */
104 eraS2c( dl, db, v1 );
105
106 /* Galactic to Supergalactic */
107 eraRxp( rmat, v1, v2 );
108
109 /* Cartesian to spherical */
110 eraC2s( v2, dsl, dsb );
111
112 /* Express in conventional ranges */
113 *dsl = eraAnp( *dsl );
114 *dsb = eraAnpm( *dsb );
115
116}
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