FACT++  1.0
palDtt.c
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1 /*
2 *+
3 * Name:
4 * palDtt
5 
6 * Purpose:
7 * Return offset between UTC and TT
8 
9 * Language:
10 * Starlink ANSI C
11 
12 * Type of Module:
13 * Library routine
14 
15 * Invocation:
16 * dtt = palDtt( double utc );
17 
18 * Arguments:
19 * utc = double (Given)
20 * UTC date as a modified JD (JD-2400000.5)
21 
22 * Returned Value:
23 * dtt = double
24 * TT-UTC in seconds
25 
26 * Description:
27 * Increment to be applied to Coordinated Universal Time UTC to give
28 * Terrestrial Time TT (formerly Ephemeris Time ET)
29 
30 * Authors:
31 * TIMJ: Tim Jenness (JAC, Hawaii)
32 * PTW: Patrick T. Wallace
33 * {enter_new_authors_here}
34 
35 * Notes:
36 * - Consider a comprehensive upgrade to use the time transformations in SOFA's time
37 * cookbook: http://www.iausofa.org/sofa_ts_c.pdf.
38 * - See eraDat for a description of error conditions when calling this function
39 * with a time outside of the UTC range. This behaviour differs from slaDtt.
40 
41 * History:
42 * 2012-02-08 (TIMJ):
43 * Initial version
44 * Adapted with permission from the Fortran SLALIB library.
45 * {enter_further_changes_here}
46 
47 * Copyright:
48 * Copyright (C) 1995 Rutherford Appleton Laboratory
49 * Copyright (C) 2012 Science and Technology Facilities Council.
50 * All Rights Reserved.
51 
52 * Licence:
53 * This program is free software: you can redistribute it and/or
54 * modify it under the terms of the GNU Lesser General Public
55 * License as published by the Free Software Foundation, either
56 * version 3 of the License, or (at your option) any later
57 * version.
58 *
59 * This program is distributed in the hope that it will be useful,
60 * but WITHOUT ANY WARRANTY; without even the implied warranty of
61 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
62 * GNU Lesser General Public License for more details.
63 *
64 * You should have received a copy of the GNU Lesser General
65 * License along with this program. If not, see
66 * <http://www.gnu.org/licenses/>.
67 
68 * Bugs:
69 * {note_any_bugs_here}
70 *-
71 */
72 
73 #include "pal.h"
74 
75 double palDtt( double utc ) {
76  return 32.184 + palDat( utc );
77 }
double palDat(double dju)
Definition: palDat.c:82
double palDtt(double utc)
Definition: palDtt.c:75