1 /* 2 * - - - - - - - - - - - 3 * g a l _ m t c 2 t t 4 * - - - - - - - - - - - 5 * 6 * This routine is part of the General Astrodynamics Library 7 * 8 * Description: 9 * 10 * This routine converts a Mars Coordinated Time (MTC) date 11 * to a TT jd date. Mars Coordinated Time is the Mean Solar 12 * Time on the Mars prime meridian. 13 * 14 * Status: 15 * 16 * support routine. 17 * 18 * Given: 19 * 20 * mtc1 d MTC date part 1 21 * mtc2 d MTC date part 2 22 * 23 * Returned: 24 * 25 * *tt1 d TT date part 1 26 * *tt2 d TT date part 2 27 * 28 * Notes: 29 * 30 * 1) As defined, consistent with the terrestrial convention for Mean 31 * Solar Time, JD 2451549.5 (2000 January 6 00:00:00) corresponds to 32 * a near coincidence of the terrestrial Greenwich mean solar 33 * midnight and the Martian mean solar (prime meridian) midnight. The 34 * addition of the integer number 44796 assures a positive result 35 * for any date since JD 2405522 (1873 December 29.5). 36 * 37 * References: 38 * 39 * A post-Pathfinder evaluation of areocentric solar coordinates with 40 * improved timing recipes for Mars seasonal/diurnal climate studies 41 * by Michael Allison, Megan McEwen, 42 * Planetary and Space Science 48 (2000) 215-235 43 * 44 * Mars24 URL: http://www.giss.nasa.gov/tools/mars24/help/algorithm.html 45 * The referenced URL contains corrections to the referenced article. 46 * 47 * This revision: 48 * 49 * 2009 January 5 50 * 51 * Copyright (C) 2009 Paul C. L. Willmott. See notes at end. 52 * 53 *----------------------------------------------------------------------- 54 */ 55 56 #ifndef _GAL_MTC2TT_H_ 57 #define _GAL_MTC2TT_H_ 1 58 59 #undef __BEGIN_DECLS 60 #undef __END_DECLS 61 #ifdef __cplusplus 62 #define __BEGIN_DECLS extern "C" { 63 #define __END_DECLS } 64 #else 65 #define __BEGIN_DECLS /* empty */ 66 #define __END_DECLS /* empty */ 67 #endif 68 69 __BEGIN_DECLS 70 71 void 72 gal_mtc2tt 73 ( 74 double mtc1, 75 double mtc2, 76 double *tt1, 77 double *tt2 78 ) ; 79 80 __END_DECLS 81 82 #endif /* !_GAL_MTC2TT_H_ */ 83 84 /* 85 * gal - General Astrodynamics Library 86 * Copyright (C) 2009 Paul C. L. Willmott 87 * 88 * This program is free software; you can redistribute it and/or modify 89 * it under the terms of the GNU General Public License as published by 90 * the Free Software Foundation; either version 2 of the License, or 91 * (at your option) any later version. 92 * 93 * This program is distributed in the hope that it will be useful, 94 * but WITHOUT ANY WARRANTY; without even the implied warranty of 95 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 96 * GNU General Public License for more details. 97 * 98 * You should have received a copy of the GNU General Public License along 99 * with this program; if not, write to the Free Software Foundation, Inc., 100 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 101 * 102 * Contact: 103 * 104 * Paul Willmott 105 * vp9mu@amsat.org 106 */ 107