| 1 | /*
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| 2 | *+
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| 3 | * Name:
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| 4 | * palDat
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| 5 |
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| 6 | * Purpose:
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| 7 | * Return offset between UTC and TAI
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| 8 |
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| 9 | * Language:
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| 10 | * Starlink ANSI C
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| 11 |
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| 12 | * Type of Module:
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| 13 | * Library routine
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| 14 |
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| 15 | * Invocation:
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| 16 | * dat = palDat( double utc );
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| 17 |
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| 18 | * Arguments:
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| 19 | * utc = double (Given)
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| 20 | * UTC date as a modified JD (JD-2400000.5)
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| 21 |
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| 22 | * Returned Value:
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| 23 | * dat = double
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| 24 | * TAI-UTC in seconds
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| 25 |
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| 26 | * Description:
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| 27 | * Increment to be applied to Coordinated Universal Time UTC to give
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| 28 | * International Atomic Time (TAI).
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| 29 |
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| 30 | * Authors:
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| 31 | * TIMJ: Tim Jenness (JAC, Hawaii)
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| 32 | * {enter_new_authors_here}
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| 33 |
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| 34 | * Notes:
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| 35 | * - This routine converts the MJD argument to calendar date before calling
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| 36 | * the SOFA/ERFA eraDat function.
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| 37 | * - This routine matches the slaDat interface which differs from the eraDat
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| 38 | * interface. Consider coding directly to the SOFA/ERFA interface.
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| 39 | * - See eraDat for a description of error conditions when calling this function
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| 40 | * with a time outside of the UTC range.
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| 41 | * - The status argument from eraDat is ignored. This is reasonable since the
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| 42 | * error codes are mainly related to incorrect calendar dates when calculating
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| 43 | * the JD internally.
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| 44 |
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| 45 | * History:
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| 46 | * 2012-02-08 (TIMJ):
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| 47 | * Initial version
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| 48 | * Adapted with permission from the Fortran SLALIB library
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| 49 | * although the core algorithm is now from SOFA.
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| 50 | * {enter_further_changes_here}
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| 51 |
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| 52 | * Copyright:
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| 53 | * Copyright (C) 2012 Science and Technology Facilities Council.
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| 54 | * All Rights Reserved.
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| 55 |
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| 56 | * Licence:
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| 57 | * This program is free software: you can redistribute it and/or
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| 58 | * modify it under the terms of the GNU Lesser General Public
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| 59 | * License as published by the Free Software Foundation, either
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| 60 | * version 3 of the License, or (at your option) any later
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| 61 | * version.
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| 62 | *
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| 63 | * This program is distributed in the hope that it will be useful,
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| 64 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 65 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 66 | * GNU Lesser General Public License for more details.
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| 67 | *
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| 68 | * You should have received a copy of the GNU Lesser General
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| 69 | * License along with this program. If not, see
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| 70 | * <http://www.gnu.org/licenses/>.
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| 71 |
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| 72 | * Bugs:
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| 73 | * {note_any_bugs_here}
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| 74 | *-
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| 75 | */
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| 76 |
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| 77 | #include "pal.h"
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| 78 | #include "palmac.h"
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| 79 |
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| 80 | #include "pal1sofa.h"
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| 81 |
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| 82 | double palDat ( double dju ) {
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| 83 | int iy;
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| 84 | int im;
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| 85 | int id;
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| 86 | int status;
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| 87 | double fd;
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| 88 | double deltat;
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| 89 |
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| 90 | eraJd2cal( PAL__MJD0, dju,
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| 91 | &iy, &im, &id, &fd );
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| 92 |
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| 93 | status = eraDat( iy, im, id, fd, &deltat );
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| 94 | return deltat;
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| 95 | }
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