1 /*
2 * - - - - - - - - - - - -
3 * g a l _ b p l p v 8 7
4 * - - - - - - - - - - - -
5 *
6 * This routine is part of the General Astrodynamics Library
7 *
8 * Description:
9 *
10 * Pluto barycentric position and velocity, with respect to the
11 * FK5 Reference Frame.
12 *
13 * Status:
14 *
15 * internal support routine.
16 *
17 * Given:
18 *
19 * tt1 d TT epoch part 1 (Note 1)
20 * tt2 d TT epoch part 2 (Note 1)
21 * ref i Reference frame
22 * 0 = dynamical equinox and ecliptic J2000.
23 * 1 = FK5 (VSOP87)
24 *
25 * Returned:
26 *
27 * pv d[2][3] position/velocity (AU, AU/Day)
28 *
29 * Called:
30 *
31 * gal_vsop87 Compute VSOP87 position and velocity
32 *
33 * Notes:
34 *
35 * 1) The epoch tt1+tt2 is a Julian Date, apportioned in
36 * any convenient way between the two arguments. For example,
37 * JD(TDB)=2450123.7 could be expressed in any of these ways,
38 * among others:
39 *
40 * tt1 tt2
41 *
42 * 2450123.7 0.0 (JD method)
43 * 2451545.0 -1421.3 (J2000 method)
44 * 2400000.5 50123.2 (MJD method)
45 * 2450123.5 0.2 (date & time method)
46 *
47 * The JD method is the most natural and convenient to use in
48 * cases where the loss of several decimal digits of resolution
49 * is acceptable. The J2000 method is best matched to the way
50 * the argument is handled internally and will deliver the
51 * optimum resolution. The MJD method and the date & time methods
52 * are both good compromises between resolution and convenience.
53 * However, the accuracy of the result is more likely to be
54 * limited by the algorithm itself than the way the epoch has been
55 * expressed.
56 *
57 * 2) On return, the arrays pvh and pvb contain the following:
58 *
59 * pv[0][0] x }
60 * pv[0][1] y } position, AU
61 * pv[0][2] z }
62 *
63 * pv[1][0] xdot }
64 * pv[1][1] ydot } velocity, AU/day
65 * pv[1][2] zdot }
66 *
67 * The vectors are barycentric with respect to the FK5 Reference Frame.
68 * The time unit is one day in TT
69 *
70 * 3) The tables of Pluto have been constructed by J. Chapront (BDL) with a new
71 * method of approximation using frequency analysis as described in the paper
72 * This representation uses the result of numerical integration DE200 of Jet
73 * Propulsion Laboratory as a source: Standish E. M., 1990, The observational
74 * basis for JPL'DE200, the planetary ephemerides of the Astronomical Almanac.
75 * Astron. Astrophys., 233, 252.
76 *
77 * 4) The interval of validity is 146120 days.
78 * Start : Jan 01 1700 0h JD2341972.5
79 * End : Jan 24 2100 0h JD2488092.5
80 *
81 * 5) The tables contain series which represent the heliocentric rectangular
82 * coordinates of Pluto as functions of time. The reference frame is defined
83 * with dynamical equinox and equator J2000 (DE200). The time scale is
84 * Barycentric Dynamical Time (TDB).
85 *
86 * References:
87 *
88 * Representation of planetary ephemerides by frequency analysis.
89 * Application to the five outer planets.
90 * Astron. & Astrophys.Suppl. Ser., 109, 191 (1995).
91 *
92 *
93 * This revision:
94 *
95 * 2009 January 9
96 *
97 * Copyright (C) 2008, 2009 Paul C. L. Willmott. See notes at end.
98 *
99 *-----------------------------------------------------------------------
100 */
101
102 #include "gal_bplpv87.h"
103 #include "gal_vsop87.h"
104 #include "gal_bsupv87.h"
105 void
gal_bplpv87(double tt1,double tt2,int ref,double pv[2][3])106 gal_bplpv87
107 (
108 double tt1,
109 double tt2,
110 int ref,
111 double pv[2][3]
112 )
113
114 {
115
116 double su[2][3], pl[2][3] ;
117
118 /*
119 * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
120 */
121
122 /*
123 * Get Sun barycentric position & velocity
124 */
125
126 gal_bsupv87 ( tt1, tt2, ref, su ) ;
127
128 /*
129 * Get Pluto heliocentric position & velocity
130 */
131
132 gal_hplpv87 ( tt1, tt2, ref, pl ) ;
133
134 /*
135 * Calculate Pluto barycentric position & velocity
136 */
137
138 gal_pvppv ( pl, su, pv ) ;
139
140 /*
141 * Finished.
142 */
143
144 }
145
146 /*
147 * gal - General Astrodynamics Library
148 * Copyright (C) 2008, 2009 Paul C. L. Willmott
149 *
150 * This program is free software; you can redistribute it and/or modify
151 * it under the terms of the GNU General Public License as published by
152 * the Free Software Foundation; either version 2 of the License, or
153 * (at your option) any later version.
154 *
155 * This program is distributed in the hope that it will be useful,
156 * but WITHOUT ANY WARRANTY; without even the implied warranty of
157 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
158 * GNU General Public License for more details.
159 *
160 * You should have received a copy of the GNU General Public License along
161 * with this program; if not, write to the Free Software Foundation, Inc.,
162 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
163 *
164 * Contact:
165 *
166 * Paul Willmott
167 * vp9mu@amsat.org
168 */
169