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00001 /************************************************************************ 00002 00003 LUNAR SOLUTION ELP2000-82B 00004 by Chapront-Touze M., Chapront J. 00005 ftp://ftp.imcce.fr/pub/ephem/moon/elp82b 00006 00007 I (Johannes Gajdosik) have just taken the Fortran code and data 00008 obtained from above and used it to create this piece of software. 00009 00010 I can neigther allow nor forbid the usage of ELP2000-82B. 00011 The copyright notice below covers not the works of 00012 Chapront-Touze M. and Chapront J., but just my work, 00013 that is the compilation and rearrangement of 00014 the Fortran code and data obtained from above 00015 into the software supplied in this file. 00016 00017 00018 Copyright (c) 2005 Johannes Gajdosik 00019 00020 Permission is hereby granted, free of charge, to any person obtaining a 00021 copy of this software and associated documentation files (the "Software"), 00022 to deal in the Software without restriction, including without limitation 00023 the rights to use, copy, modify, merge, publish, distribute, sublicense, 00024 and/or sell copies of the Software, and to permit persons to whom the 00025 Software is furnished to do so, subject to the following conditions: 00026 00027 The above copyright notice and this permission notice shall be included 00028 in all copies or substantial portions of the Software. 00029 00030 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 00031 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 00032 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 00033 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 00034 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 00035 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 00036 SOFTWARE. 00037 00038 My implementation of ELP2000-82B has the following modifications compared to 00039 the original Fortran code: 00040 1) fundamentally rearrange the series into optimized instructions 00041 for fast calculation of the results 00042 2) units are: julian day, AU 00043 00044 ****************************************************************/ 00045 00046 00047 #ifndef _ELP82B_H_ 00048 #define _ELP82B_H_ 00049 00050 #ifdef __cplusplus 00051 extern "C" { 00052 #endif 00053 00054 void GetElp82bCoor(double jd,double xyz[3]); 00055 00056 /* Return the rectangular coordinates of the earths moon 00057 on the given julian date jd expressed in dynamical time (TAI+32.184s). 00058 The origin of the xyz-coordinates is the center of the earth. 00059 The reference frame is "dynamical equinox and ecliptic J2000", 00060 which is the reference frame in VSOP87 and VSOP87A. 00061 00062 According to vsop87.doc VSOP87 coordinates can be transformed to FK5 by 00063 X cos(psi) -sin(psi) 0 1 0 0 X 00064 Y = sin(psi) cos(psi) 0 * 0 cos(eps) -sin(eps) * Y 00065 Z FK5 0 0 1 0 sin(eps) cos(eps) Z VSOP87 00066 with psi = -0.0000275 degrees = -0.099 arcsec and 00067 eps = 23.4392803055556 degrees = 23d26m21.4091sec. 00068 00069 http://ssd.jpl.nasa.gov/horizons_doc.html#frames says: 00070 "J2000" selects an Earth Mean-Equator and dynamical Equinox of 00071 Epoch J2000.0 inertial reference system, where the Epoch of J2000.0 00072 is the Julian date 2451545.0. "Mean" indicates nutation effects are 00073 ignored in the frame definition. The system is aligned with the 00074 IAU-sponsored J2000 frame of the Radio Source Catalog of the 00075 International Earth Rotational Service (ICRF). 00076 The ICRF is thought to differ from FK5 by at most 0.01 arcsec. 00077 00078 From this I conclude that in the context of stellarium 00079 ICRF, J2000 and FK5 are the same, while the transformation 00080 ICRF <-> VSOP87 must be done with the matrix given above. 00081 */ 00082 00083 00084 #ifdef __cplusplus 00085 }; 00086 #endif 00087 00088 #endif