1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
|
SUBROUTINE slS2C6 ( A, B, R, AD, BD, RD, V )
*+
* - - - - - -
* S 2 C 6
* - - - - - -
*
* Conversion of position & velocity in spherical coordinates
* to Cartesian coordinates (single precision)
*
* Given:
* A r longitude (radians)
* B r latitude (radians)
* R r radial coordinate
* AD r longitude derivative (radians per unit time)
* BD r latitude derivative (radians per unit time)
* RD r radial derivative
*
* Returned:
* V r(6) Cartesian position & velocity vector
*
* Last revision: 11 September 2005
*
* Copyright P.T.Wallace. All rights reserved.
*
* License:
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (see SLA_CONDITIONS); if not, write to the
* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301 USA
*
* Copyright (C) 1995 Association of Universities for Research in Astronomy Inc.
*-
IMPLICIT NONE
REAL A, B, R, AD, BD, RD, V(6)
REAL SA, CA, SB, CB, RCB, X, Y, RBD, W
* Useful functions.
SA = SIN(A)
CA = COS(A)
SB = SIN(B)
CB = COS(B)
RCB = R*CB
X = RCB*CA
Y = RCB*SA
RBD = R*BD
W = RBD*SB-CB*RD
* Position.
V(1) = X
V(2) = Y
V(3) = R*SB
* Velocity.
V(4) = -Y*AD-W*CA
V(5) = X*AD-W*SA
V(6) = RBD*CB+SB*RD
END
|
