Stellarium  0.90.0
elliptic_to_rectangular.h
1 /************************************************************************
2 
3 The code in this file is heavily inspired by the TASS17 and GUST86 theories
4 found on
5 ftp://ftp.imcce.fr/pub/ephem/satel
6 
7 I (Johannes Gajdosik) have just taken the Fortran code and data
8 obtained from above and rearranged it into this piece of software.
9 
10 I can neither allow nor forbid the above theories.
11 The copyright notice below covers just my work,
12 that is the compilation of the data obtained from above
13 into the software supplied in this file.
14 
15 
16 Copyright (c) 2005 Johannes Gajdosik
17 
18 Permission is hereby granted, free of charge, to any person obtaining a
19 copy of this software and associated documentation files (the "Software"),
20 to deal in the Software without restriction, including without limitation
21 the rights to use, copy, modify, merge, publish, distribute, sublicense,
22 and/or sell copies of the Software, and to permit persons to whom the
23 Software is furnished to do so, subject to the following conditions:
24 
25 The above copyright notice and this permission notice shall be included
26 in all copies or substantial portions of the Software.
27 
28 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
29 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
30 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
31 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
32 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
33 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
34 SOFTWARE.
35 
36 ****************************************************************/
37 
38 #ifndef _ELLIPTIC_TO_RECTANGULAR_
39 #define _ELLIPTIC_TO_RECTANGULAR_
40 
41 #ifdef __cplusplus
42 extern "C" {
43 #endif
44 
45 /*
46  Given the orbital elements at some time t0 calculate the
47  rectangular coordinates at time (t0+dt).
48 
49  mu = G*(m1+m2) .. gravitational constant of the two body problem
50  a .. semi major axis
51  n = mean motion = 2*M_PI/(orbit period)
52 
53  elem[0] .. either a (EllipticToRectangularA()) or n (EllipticToRectangularN())
54  elem[1] .. L
55  elem[2] .. K=e*cos(Omega+omega)
56  elem[3] .. H=e*sin(Omega+omega)
57  elem[4] .. Q=sin(i/2)*cos(Omega)
58  elem[5] .. P=sin(i/2)*sin(Omega)
59 
60  Omega = longitude of ascending node
61  omega = argument of pericenter
62  L = mean longitude = Omega + omega + M
63  M = mean anomaly
64  i = inclination
65  e = excentricity
66 
67  Units are suspected to be: Julian days, AU, rad
68 */
69 
70 void EllipticToRectangularN(double mu,const double elem[6],double dt,
71  double xyz[]);
72 void EllipticToRectangularA(double mu,const double elem[6],double dt,
73  double xyz[]);
74 
75 #ifdef __cplusplus
76 }
77 #endif
78 
79 #endif