Estimate sampling patterns of AIRS. More...
#include "libairs.h"Go to the source code of this file.
Functions | |
| int | main (int argc, char *argv[]) |
Detailed Description
Estimate sampling patterns of AIRS.
Definition in file sampling.c.
Function Documentation
◆ main()
| int main | ( | int | argc, |
| char * | argv[] | ||
| ) |
Definition at line 28 of file sampling.c.
30 {
31
33
34 double x0[3], x1[3], x2[3];
35
36 /* Check arguments... */
37 if (argc < 3)
38 ERRMSG("Give parameters: <ctl> <pert.nc>");
39
40 /* Allocate... */
41 ALLOC(pert, pert_t, 1);
42
43 /* Read perturbation data... */
45
46 /* Init... */
47 double dmin = 1e100;
48 double dmax = -1e100;
49 double dmu = 0;
50 int n = 0;
51
52 /* Get swath width... */
57 double d = 2. * RE * asin(DIST(x0, x1) / (2. * RE));
58 dmin = GSL_MIN(dmin, d);
59 dmax = GSL_MAX(dmax, d);
60 dmu += d;
61 n++;
62 }
63
64 /* Write output... */
65 printf("\nmean_swath_width= %.1f km\n", dmu / n);
66 printf("minimum_swath_width= %.1f km\n", dmin);
67 printf("maximum_swath_width= %.1f km\n", dmax);
68
69 /* Init... */
70 dmin = 1e100;
71 dmax = -1e100;
72 dmu = 0;
73 n = 0;
74
75 /* Get across-track sampling distances... */
79 geo2cart(0, pert->lon[itrack][ixtrack + 1],
80 pert->lat[itrack][ixtrack + 1], x1);
81 double d = 2. * RE * asin(DIST(x0, x1) / (2. * RE));
82 dmin = GSL_MIN(dmin, d);
83 dmax = GSL_MAX(dmax, d);
84 dmu += d;
85 n++;
86 }
87 }
88
89 /* Write output... */
90 printf("\nmean_across_track_sampling_distance= %.1f km\n", dmu / n);
91 printf("minimum_across_track_sampling_distance= %.1f km\n", dmin);
92 printf("maximum_across_track_sampling_distance= %.1f km\n", dmax);
93
94 /* Init... */
95 dmin = 1e100;
96 dmax = -1e100;
97 dmu = 0;
98 n = 0;
99
100 /* Get along-track sampling distances... */
104 geo2cart(0, pert->lon[itrack + 1][ixtrack],
105 pert->lat[itrack + 1][ixtrack], x1);
106 double d = 2. * RE * asin(DIST(x0, x1) / (2. * RE));
107 dmin = GSL_MIN(dmin, d);
108 dmax = GSL_MAX(dmax, d);
109 dmu += d;
110 n++;
111 }
112 }
113
114 /* Write output... */
115 printf("\nmean_along_track_sampling_distance= %.1f km\n", dmu / n);
116 printf("minimum_along_track_sampling_distance= %.1f km\n", dmin);
117 printf("maximum_along_track_sampling_distance= %.1f km\n", dmax);
118
119 /* Init... */
120 dmin = 1e100;
121 dmax = -1e100;
122 dmu = 0;
123 n = 0;
124
125 /* Get angle between along-track and across-track direction... */
133 for (int i = 0; i < 3; i++) {
134 x1[i] -= x0[i];
135 x2[i] -= x0[i];
136 }
137 double d = acos(DOTP(x1, x2) / (NORM(x1) * NORM(x2))) * 180. / M_PI;
138 dmin = GSL_MIN(dmin, d);
139 dmax = GSL_MAX(dmax, d);
140 dmu += d;
141 n++;
142 }
143
144 /* Write output... */
145 printf("\nmean_across_track_angle= %.1f deg\n", dmu / n);
146 printf("minimum_across_track_angle= %.1f deg\n", dmin);
147 printf("maximum_across_track_angle= %.1f deg\n", dmax);
148
149 /* Free... */
150 free(pert);
151
152 return EXIT_SUCCESS;
153}
void read_pert(char *filename, char *pertname, pert_t *pert)
Read radiance perturbation data.
Definition: libairs.c:1137
Here is the call graph for this function:
