FACT++  1.0
pal1Atms.c
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1 /*
2 *+
3 * Name:
4 * pal1Atms
5 
6 * Purpose:
7 * Calculate stratosphere parameters
8 
9 * Language:
10 * Starlink ANSI C
11 
12 * Type of Module:
13 * Library routine
14 
15 * Invocation:
16 * void pal1Atms ( double rt, double tt, double dnt, double gamal,
17 * double r, double * dn, double * rdndr );
18 
19 * Arguments:
20 * rt = double (Given)
21 * Height of the tropopause from centre of the Earth (metre)
22 * tt = double (Given)
23 * Temperature at the tropopause (K)
24 * dnt = double (Given)
25 * Refractive index at the tropopause
26 * gamal = double (Given)
27 * Constant of the atmospheric model = G*MD/R
28 * r = double (Given)
29 * Current distance from the centre of the Earth (metre)
30 * dn = double * (Returned)
31 * Refractive index at r
32 * rdndr = double * (Returned)
33 * r * rate the refractive index is changing at r
34 
35 * Description:
36 * Refractive index and derivative with respect to height for the
37 * stratosphere.
38 
39 * Authors:
40 * TIMJ: Tim Jenness (JAC, Hawaii)
41 * PTW: Patrick T. Wallace
42 * {enter_new_authors_here}
43 
44 * Notes:
45 * - Internal routine used by palRefro.
46 
47 * History:
48 * 2012-08-24 (TIMJ):
49 * Initial version
50 * Adapted with permission from the Fortran SLALIB library.
51 * {enter_further_changes_here}
52 
53 * Copyright:
54 * Copyright (C) 2004 Patrick T. Wallace
55 * Copyright (C) 2012 Science and Technology Facilities Council.
56 * All Rights Reserved.
57 
58 * Licence:
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License as
61 * published by the Free Software Foundation; either version 3 of
62 * the License, or (at your option) any later version.
63 *
64 * This program is distributed in the hope that it will be
65 * useful, but WITHOUT ANY WARRANTY; without even the implied
66 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
67 * PURPOSE. See the GNU General Public License for more details.
68 *
69 * You should have received a copy of the GNU General Public License
70 * along with this program; if not, write to the Free Software
71 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
72 * MA 02110-1301, USA.
73 
74 * Bugs:
75 * {note_any_bugs_here}
76 *-
77 */
78 
79 #include <math.h>
80 
81 #include "pal1.h"
82 
83 void pal1Atms ( double rt, double tt, double dnt, double gamal,
84  double r, double * dn, double * rdndr ) {
85 
86  double b;
87  double w;
88 
89  b = gamal / tt;
90  w = (dnt - 1.0) * exp( -b * (r-rt) );
91  *dn = 1.0 + w;
92  *rdndr = -r * b * w;
93 
94 }
95 
pal1Atms
void pal1Atms(double rt, double tt, double dnt, double gamal, double r, double *dn, double *rdndr)
Definition: pal1Atms.c:83