File Coverage

palsrc/palRvgalc.c
Criterion Covered Total %
statement 0 4 0.0
branch n/a
condition n/a
subroutine n/a
pod n/a
total 0 4 0.0


line stmt bran cond sub pod time code
1             /*
2             *+
3             * Name:
4             * palRvgalc
5              
6             * Purpose:
7             * Velocity component in a given direction due to the rotation
8             * of the Galaxy.
9              
10             * Language:
11             * Starlink ANSI C
12              
13             * Type of Module:
14             * Library routine
15              
16             * Invocation:
17             * double palRvgalc( double r2000, double d2000 )
18              
19             * Arguments:
20             * r2000 = double (Given)
21             * J2000.0 mean RA (radians)
22             * d2000 = double (Given)
23             * J2000.0 mean Dec (radians)
24              
25             * Returned Value:
26             * Component of dynamical LSR motion in direction R2000,D2000 (km/s).
27              
28             * Description:
29             * This function returns the Component of dynamical LSR motion in
30             * the direction of R2000,D2000. The result is +ve when the dynamical
31             * LSR is receding from the given point on the sky.
32             *
33             * Notes:
34             * - The Local Standard of Rest used here is a point in the
35             * vicinity of the Sun which is in a circular orbit around
36             * the Galactic centre. Sometimes called the "dynamical" LSR,
37             * it is not to be confused with a "kinematical" LSR, which
38             * is the mean standard of rest of star catalogues or stellar
39             * populations.
40             *
41             * Reference:
42             * - The orbital speed of 220 km/s used here comes from Kerr &
43             * Lynden-Bell (1986), MNRAS, 221, p1023.
44              
45             * Authors:
46             * PTW: Pat Wallace (STFC)
47             * DSB: David Berry (JAC, Hawaii)
48             * {enter_new_authors_here}
49              
50             * History:
51             * 2012-02-16 (DSB):
52             * Initial version.
53             * Adapted with permission from the Fortran SLALIB library.
54             * {enter_further_changes_here}
55              
56             * Copyright:
57             * Copyright (C) 1995 Rutherford Appleton Laboratory
58             * Copyright (C) 2012 Science and Technology Facilities Council.
59             * All Rights Reserved.
60              
61             * Licence:
62             * This program is free software: you can redistribute it and/or
63             * modify it under the terms of the GNU Lesser General Public
64             * License as published by the Free Software Foundation, either
65             * version 3 of the License, or (at your option) any later
66             * version.
67             *
68             * This program is distributed in the hope that it will be useful,
69             * but WITHOUT ANY WARRANTY; without even the implied warranty of
70             * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
71             * GNU Lesser General Public License for more details.
72             *
73             * You should have received a copy of the GNU Lesser General
74             * License along with this program. If not, see
75             * .
76              
77             * Bugs:
78             * {note_any_bugs_here}
79             *-
80             */
81              
82             #include "pal.h"
83             #include "pal1sofa.h"
84              
85 0           double palRvgalc( double r2000, double d2000 ){
86              
87             /* Local Variables: */
88             double vb[ 3 ];
89              
90             /*
91             * LSR velocity due to Galactic rotation
92             *
93             * Speed = 220 km/s
94             * Apex = L2,B2 90deg, 0deg
95             * = RA,Dec 21 12 01.1 +48 19 47 J2000.0
96             *
97             * This is expressed in the form of a J2000.0 x,y,z vector:
98             *
99             * VA(1) = X = -SPEED*COS(RA)*COS(DEC)
100             * VA(2) = Y = -SPEED*SIN(RA)*COS(DEC)
101             * VA(3) = Z = -SPEED*SIN(DEC)
102             */
103              
104 0           double va[ 3 ] = { -108.70408, +97.86251, -164.33610 };
105              
106             /* Convert given J2000 RA,Dec to x,y,z. */
107 0           eraS2c( r2000, d2000, vb );
108              
109             /* Compute dot product with LSR motion vector. */
110 0           return eraPdp( va, vb );
111             }