/[radiance]/ray/src/gen/gendaylit.c
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Contents of /ray/src/gen/gendaylit.c

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Revision 2.17 - (show annotations) (download)
Fri Aug 31 16:01:45 2018 UTC (10 months, 2 weeks ago) by greg
Branch: MAIN
CVS Tags: rad5R2, HEAD
Changes since 2.16: +61 -9 lines
File MIME type: text/plain
New versions of evalglare and gendaylit from Jan Wienold

1 /* Copyright (c) 1994,2006 *Fraunhofer Institut for Solar Energy Systems
2 * Heidenhofstr. 2, D-79110 Freiburg, Germany
3 * *Agence de l'Environnement et de la Maitrise de l'Energie
4 * Centre de Valbonne, 500 route des Lucioles, 06565 Sophia Antipolis Cedex, France
5 * *BOUYGUES
6 * 1 Avenue Eugene Freyssinet, Saint-Quentin-Yvelines, France
7 * print colored output if activated in command line (-C). Based on model from A. Diakite, TU-Berlin. Implemented by J. Wienold, August 26 2018
8 */
9
10 #define _USE_MATH_DEFINES
11 #include <stdio.h>
12 #include <string.h>
13 #include <math.h>
14 #include <stdlib.h>
15
16 #include "color.h"
17 #include "sun.h"
18 #include "paths.h"
19
20 #define DOT(v1,v2) (v1[0]*v2[0]+v1[1]*v2[1]+v1[2]*v2[2])
21
22 double normsc();
23
24 /*static char *rcsid="$Header: /usr/local/cvs/radiance/ray/src/gen/gendaylit.c,v 2.16 2014/07/30 17:30:27 greg Exp $";*/
25
26 float coeff_perez[] = {
27 1.3525,-0.2576,-0.2690,-1.4366,-0.7670,0.0007,1.2734,-0.1233,2.8000,0.6004,1.2375,1.000,1.8734,0.6297,
28 0.9738,0.2809,0.0356,-0.1246,-0.5718,0.9938,-1.2219,-0.7730,1.4148,1.1016,-0.2054,0.0367,-3.9128,0.9156,
29 6.9750,0.1774,6.4477,-0.1239,-1.5798,-0.5081,-1.7812,0.1080,0.2624,0.0672,-0.2190,-0.4285,-1.1000,-0.2515,
30 0.8952,0.0156,0.2782,-0.1812,-4.5000,1.1766,24.7219,-13.0812,-37.7000,34.8438,-5.0000,1.5218,3.9229,
31 -2.6204,-0.0156,0.1597,0.4199,-0.5562,-0.5484,-0.6654,-0.2672,0.7117,0.7234,-0.6219,-5.6812,2.6297,
32 33.3389,-18.3000,-62.2500,52.0781,-3.5000,0.0016,1.1477,0.1062,0.4659,-0.3296,-0.0876,-0.0329,-0.6000,
33 -0.3566,-2.5000,2.3250,0.2937,0.0496,-5.6812,1.8415,21.0000,-4.7656,-21.5906,7.2492,-3.5000,-0.1554,
34 1.4062,0.3988,0.0032,0.0766,-0.0656,-0.1294,-1.0156,-0.3670,1.0078,1.4051,0.2875,-0.5328,-3.8500,3.3750,
35 14.0000,-0.9999,-7.1406,7.5469,-3.4000,-0.1078,-1.0750,1.5702,-0.0672,0.4016,0.3017,-0.4844,-1.0000,
36 0.0211,0.5025,-0.5119,-0.3000,0.1922,0.7023,-1.6317,19.0000,-5.0000,1.2438,-1.9094,-4.0000,0.0250,0.3844,
37 0.2656,1.0468,-0.3788,-2.4517,1.4656,-1.0500,0.0289,0.4260,0.3590,-0.3250,0.1156,0.7781,0.0025,31.0625,
38 -14.5000,-46.1148,55.3750,-7.2312,0.4050,13.3500,0.6234,1.5000,-0.6426,1.8564,0.5636};
39
40
41 float defangle_theta[] = {
42 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84,
43 84, 84, 84, 84, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72, 72,
44 72, 72, 72, 72, 72, 72, 72, 72, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60,
45 60, 60, 60, 60, 60, 60, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48,
46 48, 48, 48, 48, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 24, 24, 24, 24,
47 24, 24, 24, 24, 24, 24, 24, 24, 12, 12, 12, 12, 12, 12, 0};
48
49 float defangle_phi[] = {
50 0, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, 240, 252, 264,
51 276, 288, 300, 312, 324, 336, 348, 0, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180,
52 192, 204, 216, 228, 240, 252, 264, 276, 288, 300, 312, 324, 336, 348, 0, 15, 30, 45, 60, 75, 90, 105,
53 120, 135, 150, 165, 180, 195, 210, 225, 240, 255, 270, 285, 300, 315, 330, 345, 0, 15, 30, 45, 60, 75,
54 90, 105, 120, 135, 150, 165, 180, 195, 210, 225, 240, 255, 270, 285, 300, 315, 330, 345, 0, 20, 40, 60,
55 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 0, 30, 60, 90, 120, 150, 180, 210,
56 240, 270, 300, 330, 0, 60, 120, 180, 240, 300, 0};
57 /* default values for Berlin */
58 float locus[] = {
59 -4.843e9,2.5568e6,0.24282e3,0.23258,-4.843e9,2.5568e6,0.24282e3,0.23258,-1.2848,1.7519,-0.093786};
60
61
62
63 /* Perez sky parametrization: epsilon and delta calculations from the direct and diffuse irradiances */
64 double sky_brightness();
65 double sky_clearness();
66
67 /* calculation of the direct and diffuse components from the Perez parametrization */
68 double diffuse_irradiance_from_sky_brightness();
69 double direct_irradiance_from_sky_clearness();
70
71 /* Perez global horizontal, diffuse horizontal and direct normal luminous efficacy models : */
72 /* input w(cm)=2cm, solar zenith angle(degrees); output efficacy(lm/W) */
73
74 double glob_h_effi_PEREZ();
75 double glob_h_diffuse_effi_PEREZ();
76 double direct_n_effi_PEREZ();
77
78 /*likelihood check of the epsilon, delta, direct and diffuse components*/
79 void check_parametrization();
80 void check_irradiances();
81 void check_illuminances();
82 void illu_to_irra_index();
83 void print_error_sky();
84
85 double calc_rel_lum_perez(double dzeta,double gamma,double Z,double epsilon,double Delta,float coeff_perez[]);
86 void coeff_lum_perez(double Z, double epsilon, double Delta, float coeff_perez[]);
87 double radians(double degres);
88 double degres(double radians);
89 void theta_phi_to_dzeta_gamma(double theta,double phi,double *dzeta,double *gamma, double Z);
90 double integ_lv(float *lv,float *theta);
91
92 void printdefaults();
93 void check_sun_position();
94 void computesky();
95 void printhead(int ac, char** av);
96 void usage_error(char* msg);
97 void printsky();
98
99 FILE * frlibopen(char* fname);
100
101 /* astronomy and geometry*/
102 double get_eccentricity();
103 double air_mass();
104
105 double solar_sunset(int month, int day);
106 double solar_sunrise(int month, int day);
107 double stadj();
108 int jdate(int month, int day);
109
110 const double AU = 149597890E3;
111 const double solar_constant_e = 1367; /* solar constant W/m^2 */
112 const double solar_constant_l = 127500; /* solar constant lux */
113
114 const double half_sun_angle = 0.2665;
115 const double half_direct_angle = 2.85;
116
117 const double skyclearinf = 1.0; /* limitations for the variation of the Perez parameters */
118 const double skyclearsup = 12.01;
119 const double skybriginf = 0.01;
120 const double skybrigsup = 0.6;
121
122
123
124 /* required values */
125 int month, day; /* date */
126 double hour; /* time */
127 int tsolar; /* 0=standard, 1=solar */
128 double altitude, azimuth; /* or solar angles */
129
130
131
132 /* definition of the sky conditions through the Perez parametrization */
133 double skyclearness = 0;
134 double skybrightness = 0;
135 double solarradiance;
136 double diffuseilluminance, directilluminance, diffuseirradiance, directirradiance, globalirradiance;
137 double sunzenith, daynumber, atm_preci_water=2;
138
139 /*double sunaltitude_border = 0;*/
140 double diffnormalization = 0;
141 double dirnormalization = 0;
142 double *c_perez;
143
144 int output=0; /* define the unit of the output (sky luminance or radiance): */
145 /* visible watt=0, solar watt=1, lumen=2 */
146 int input=0; /* define the input for the calulation */
147 int color_output=0;
148 int suppress_warnings=0;
149
150 /* default values */
151 int cloudy = 0; /* 1=standard, 2=uniform */
152 int dosun = 1;
153 double zenithbr = -1.0;
154 double betaturbidity = 0.1;
155 double gprefl = 0.2;
156 int S_INTER=0;
157
158
159 /* computed values */
160 double sundir[3];
161 double groundbr = 0;
162 double F2;
163 double solarbr = 0.0;
164 int u_solar = 0; /* -1=irradiance, 1=radiance */
165 float timeinterval = 0;
166
167 char *progname;
168 char errmsg[128];
169
170 double st;
171
172
173 int main(int argc, char** argv)
174 {
175 int i;
176
177 progname = argv[0];
178 if (argc == 2 && !strcmp(argv[1], "-defaults")) {
179 printdefaults();
180 return 0;
181 }
182 if (argc < 4)
183 usage_error("arg count");
184 if (!strcmp(argv[1], "-ang")) {
185 altitude = atof(argv[2]) * (M_PI/180);
186 azimuth = atof(argv[3]) * (M_PI/180);
187 month = 0;
188 } else {
189 month = atoi(argv[1]);
190 if (month < 1 || month > 12)
191 usage_error("bad month");
192 day = atoi(argv[2]);
193 if (day < 1 || day > 31)
194 usage_error("bad day");
195 hour = atof(argv[3]);
196 if (hour < 0 || hour >= 24)
197 usage_error("bad hour");
198 tsolar = argv[3][0] == '+';
199 }
200 for (i = 4; i < argc; i++)
201 if (argv[i][0] == '-' || argv[i][0] == '+')
202 switch (argv[i][1]) {
203 case 's':
204 cloudy = 0;
205 dosun = argv[i][0] == '+';
206 break;
207 case 'R':
208 u_solar = argv[i][1] == 'R' ? -1 : 1;
209 solarbr = atof(argv[++i]);
210 break;
211 case 'c':
212 cloudy = argv[i][0] == '+' ? 2 : 1;
213 dosun = 0;
214 break;
215 case 'C':
216 if (argv[i][2] == 'I' && argv[i][3] == 'E' ) {
217 locus[0] = -4.607e9;
218 locus[1] = 2.9678e6;
219 locus[2] = 0.09911e3;
220 locus[3] = 0.244063;
221 locus[4] = -2.0064e9;
222 locus[5] = 1.9018e6;
223 locus[6] = 0.24748e3;
224 locus[7] = 0.23704;
225 locus[8] = -3.0;
226 locus[9] = 2.87;
227 locus[10] = -0.275;
228 }else{ color_output = 1;
229 }
230 break;
231 case 'l':
232 locus[0] = atof(argv[++i]);
233 locus[1] = atof(argv[++i]);
234 locus[2] = atof(argv[++i]);
235 locus[3] = atof(argv[++i]);
236 locus[4] = locus[0];
237 locus[5] = locus[1];
238 locus[6] = locus[2];
239 locus[7] = locus[3];
240 locus[8] = atof(argv[++i]);
241 locus[9] = atof(argv[++i]);
242 locus[10] = atof(argv[++i]);
243 break;
244
245 case 't':
246 betaturbidity = atof(argv[++i]);
247 break;
248 case 'w':
249 suppress_warnings = 1;
250 break;
251 case 'b':
252 zenithbr = atof(argv[++i]);
253 break;
254 case 'g':
255 gprefl = atof(argv[++i]);
256 break;
257 case 'a':
258 s_latitude = atof(argv[++i]) * (M_PI/180);
259 break;
260 case 'o':
261 s_longitude = atof(argv[++i]) * (M_PI/180);
262 break;
263 case 'm':
264 s_meridian = atof(argv[++i]) * (M_PI/180);
265 break;
266
267 case 'O':
268 output = atof(argv[++i]); /*define the unit of the output of the program:
269 sky and sun luminance/radiance
270 (0==W visible, 1==W solar radiation, 2==lm) */
271 break;
272
273 case 'P':
274 input = 0; /* Perez parameters: epsilon, delta */
275 skyclearness = atof(argv[++i]);
276 skybrightness = atof(argv[++i]);
277 break;
278
279 case 'W': /* direct normal Irradiance [W/m^2] */
280 input = 1; /* diffuse horizontal Irrad. [W/m^2] */
281 directirradiance = atof(argv[++i]);
282 diffuseirradiance = atof(argv[++i]);
283 break;
284
285 case 'L': /* direct normal Illuminance [Lux] */
286 input = 2; /* diffuse horizontal Ill. [Lux] */
287 directilluminance = atof(argv[++i]);
288 diffuseilluminance = atof(argv[++i]);
289 break;
290
291 case 'G': /* direct horizontal Irradiance [W/m^2] */
292 input = 3; /* diffuse horizontal Irrad. [W/m^2] */
293 directirradiance = atof(argv[++i]);
294 diffuseirradiance = atof(argv[++i]);
295 break;
296
297 case 'E': /* Erbs model based on the */
298 input = 4; /* global-horizontal irradiance [W/m^2] */
299 globalirradiance = atof(argv[++i]);
300 break;
301
302 case 'i':
303 timeinterval = atof(argv[++i]);
304 break;
305
306
307 default:
308 sprintf(errmsg, "unknown option: %s", argv[i]);
309 usage_error(errmsg);
310 }
311 else
312 usage_error("bad option");
313
314 if (month && !tsolar && fabs(s_meridian-s_longitude) > 45*M_PI/180)
315 fprintf(stderr,"%s: warning: %.1f hours btwn. standard meridian and longitude\n",
316 progname, (s_longitude-s_meridian)*12/M_PI);
317
318
319 /* dynamic memory allocation for the pointers */
320 if ( (c_perez = calloc(5, sizeof(double))) == NULL )
321 { fprintf(stderr,"Out of memory error in function main"); return 1; }
322
323
324 printhead(argc, argv);
325 computesky();
326 printsky();
327 return 0;
328
329 }
330
331
332
333
334
335 void computesky()
336 {
337
338 int j;
339
340 float *lv_mod; /* 145 luminance values */
341 float *theta_o, *phi_o;
342 double dzeta, gamma;
343 double normfactor;
344 double erbs_s0, erbs_kt;
345
346
347 /* compute solar direction */
348
349 if (month) { /* from date and time */
350 int jd;
351 double sd;
352
353 jd = jdate(month, day); /* Julian date */
354 sd = sdec(jd); /* solar declination */
355 if (tsolar) /* solar time */
356 st = hour;
357 else
358 st = hour + stadj(jd);
359
360
361 if(timeinterval) {
362
363 if(timeinterval<0) {
364 fprintf(stderr, "time interval negative\n");
365 exit(1);
366 }
367
368 if(fabs(solar_sunrise(month,day)-st)<=timeinterval/120) {
369 st= (st+timeinterval/120+solar_sunrise(month,day))/2;
370 if(suppress_warnings==0)
371 { fprintf(stderr, "Solar position corrected at time step %d %d %.3f\n",month,day,hour); }
372 }
373
374 if(fabs(solar_sunset(month,day)-st)<timeinterval/120) {
375 st= (st-timeinterval/120+solar_sunset(month,day))/2;
376 if(suppress_warnings==0)
377 { fprintf(stderr, "Solar position corrected at time step %d %d %.3f\n",month,day,hour); }
378 }
379
380 if((st<solar_sunrise(month,day)-timeinterval/120) || (st>solar_sunset(month,day)+timeinterval/120)) {
381 if(suppress_warnings==0)
382 { fprintf(stderr, "Warning: sun position too low, printing error sky at %d %d %.3f\n",month,day,hour); }
383 altitude = salt(sd, st);
384 azimuth = sazi(sd, st);
385 print_error_sky();
386 exit(0);
387 }
388 }
389 else
390
391 if(st<solar_sunrise(month,day) || st>solar_sunset(month,day)) {
392 if(suppress_warnings==0)
393 { fprintf(stderr, "Warning: sun altitude below zero at time step %i %i %.2f, printing error sky\n",month,day,hour); }
394 altitude = salt(sd, st);
395 azimuth = sazi(sd, st);
396 print_error_sky();
397 exit(0);
398 }
399
400 altitude = salt(sd, st);
401 azimuth = sazi(sd, st);
402
403 daynumber = (double)jdate(month, day);
404
405 }
406
407
408
409
410
411 if (!cloudy && altitude > 87.*M_PI/180.) {
412
413 if (suppress_warnings==0) {
414 fprintf(stderr,
415 "%s: warning - sun too close to zenith, reducing altitude to 87 degrees\n",
416 progname);
417 }
418 altitude = 87.*M_PI/180.;
419 }
420
421
422
423 sundir[0] = -sin(azimuth)*cos(altitude);
424 sundir[1] = -cos(azimuth)*cos(altitude);
425 sundir[2] = sin(altitude);
426
427
428 /* calculation for the new functions */
429 sunzenith = 90 - altitude*180/M_PI;
430
431
432 /* compute the inputs for the calculation of the light distribution over the sky*/
433 if (input==0) /* P */
434 {
435 check_parametrization();
436 diffuseirradiance = diffuse_irradiance_from_sky_brightness(); /*diffuse horizontal irradiance*/
437 directirradiance = direct_irradiance_from_sky_clearness();
438 check_irradiances();
439
440 if (output==0 || output==2)
441 {
442 diffuseilluminance = diffuseirradiance*glob_h_diffuse_effi_PEREZ();/*diffuse horizontal illuminance*/
443 directilluminance = directirradiance*direct_n_effi_PEREZ();
444 check_illuminances();
445 }
446 }
447
448
449 else if (input==1) /* W */
450 {
451 check_irradiances();
452 skybrightness = sky_brightness();
453 skyclearness = sky_clearness();
454
455 check_parametrization();
456
457 if (output==0 || output==2)
458 {
459 diffuseilluminance = diffuseirradiance*glob_h_diffuse_effi_PEREZ();/*diffuse horizontal illuminance*/
460 directilluminance = directirradiance*direct_n_effi_PEREZ();
461 check_illuminances();
462 }
463
464 }
465
466
467 else if (input==2) /* L */
468 {
469 check_illuminances();
470 illu_to_irra_index();
471 check_parametrization();
472 }
473
474
475 else if (input==3) /* G */
476 {
477 if (altitude<=0)
478 {
479 if (suppress_warnings==0)
480 fprintf(stderr, "Warning: sun altitude < 0, proceed with irradiance values of zero\n");
481 directirradiance = 0;
482 diffuseirradiance = 0;
483 } else {
484
485 directirradiance=directirradiance/sin(altitude);
486 }
487
488 check_irradiances();
489 skybrightness = sky_brightness();
490 skyclearness = sky_clearness();
491 check_parametrization();
492
493 if (output==0 || output==2)
494 {
495 diffuseilluminance = diffuseirradiance*glob_h_diffuse_effi_PEREZ();/*diffuse horizontal illuminance*/
496 directilluminance = directirradiance*direct_n_effi_PEREZ();
497 check_illuminances();
498 }
499
500 }
501
502
503 else if (input==4) /* E */ /* Implementation of the Erbs model. W.Sprenger (04/13) */
504 {
505
506 if (altitude<=0)
507 {
508 if (suppress_warnings==0 && globalirradiance > 50)
509 fprintf(stderr, "Warning: global irradiance higher than 50 W/m^2 while the sun altitude is lower than zero\n");
510 globalirradiance = 0; diffuseirradiance = 0; directirradiance = 0;
511
512 } else {
513
514 erbs_s0 = solar_constant_e*get_eccentricity()*sin(altitude);
515
516 if (globalirradiance>erbs_s0)
517 {
518 if (suppress_warnings==0)
519 fprintf(stderr, "Warning: global irradiance is higher than the time-dependent solar constant s0\n");
520 globalirradiance=erbs_s0*0.999;
521 }
522
523 erbs_kt=globalirradiance/erbs_s0;
524
525 if (erbs_kt<=0.22) diffuseirradiance=globalirradiance*(1-0.09*erbs_kt);
526 else if (erbs_kt<=0.8) diffuseirradiance=globalirradiance*(0.9511-0.1604*erbs_kt+4.388*pow(erbs_kt,2)-16.638*pow(erbs_kt,3)+12.336*pow(erbs_kt,4));
527 else if (erbs_kt<1) diffuseirradiance=globalirradiance*(0.165);
528
529 directirradiance=globalirradiance-diffuseirradiance;
530
531 printf("# erbs_s0, erbs_kt, irr_dir_h, irr_diff: %.3f %.3f %.3f %.3f\n", erbs_s0, erbs_kt, directirradiance, diffuseirradiance);
532 printf("# WARNING: the -E option is only recommended for a rough estimation!\n");
533
534 directirradiance=directirradiance/sin(altitude);
535
536 }
537
538 check_irradiances();
539 skybrightness = sky_brightness();
540 skyclearness = sky_clearness();
541 check_parametrization();
542
543 if (output==0 || output==2)
544 {
545 diffuseilluminance = diffuseirradiance*glob_h_diffuse_effi_PEREZ();/*diffuse horizontal illuminance*/
546 directilluminance = directirradiance*direct_n_effi_PEREZ();
547 check_illuminances();
548 }
549
550 }
551
552
553
554
555 else { fprintf(stderr,"error at the input arguments"); exit(1); }
556
557
558
559 /* normalization factor for the relative sky luminance distribution, diffuse part*/
560
561 if ( (lv_mod = malloc(145*sizeof(float))) == NULL)
562 {
563 fprintf(stderr,"Out of memory in function main");
564 exit(1);
565 }
566
567 /* read the angles */
568 theta_o = defangle_theta;
569 phi_o = defangle_phi;
570
571
572 /* parameters for the perez model */
573 coeff_lum_perez(radians(sunzenith), skyclearness, skybrightness, coeff_perez);
574
575
576
577 /*calculation of the modelled luminance */
578 for (j=0;j<145;j++)
579 {
580 theta_phi_to_dzeta_gamma(radians(*(theta_o+j)),radians(*(phi_o+j)),&dzeta,&gamma,radians(sunzenith));
581
582 *(lv_mod+j) = calc_rel_lum_perez(dzeta,gamma,radians(sunzenith),skyclearness,skybrightness,coeff_perez);
583
584 /* fprintf(stderr,"theta, phi, lv_mod %f\t %f\t %f\n", *(theta_o+j),*(phi_o+j),*(lv_mod+j)); */
585 }
586
587 /* integration of luminance for the normalization factor, diffuse part of the sky*/
588
589 diffnormalization = integ_lv(lv_mod, theta_o);
590
591
592
593 /*normalization coefficient in lumen or in watt*/
594 if (output==0)
595 {
596 diffnormalization = diffuseilluminance/diffnormalization/WHTEFFICACY;
597 }
598 else if (output==1)
599 {
600 diffnormalization = diffuseirradiance/diffnormalization;
601 }
602 else if (output==2)
603 {
604 diffnormalization = diffuseilluminance/diffnormalization;
605 }
606
607 else {fprintf(stderr,"Wrong output specification.\n"); exit(1);}
608
609
610
611
612 /* calculation for the solar source */
613 if (output==0)
614 solarradiance = directilluminance/(2*M_PI*(1-cos(half_sun_angle*M_PI/180)))/WHTEFFICACY;
615
616 else if (output==1)
617 solarradiance = directirradiance/(2*M_PI*(1-cos(half_sun_angle*M_PI/180)));
618
619 else
620 solarradiance = directilluminance/(2*M_PI*(1-cos(half_sun_angle*M_PI/180)));
621
622
623
624 /* Compute the ground radiance */
625 zenithbr=calc_rel_lum_perez(0.0,radians(sunzenith),radians(sunzenith),skyclearness,skybrightness,coeff_perez);
626 zenithbr*=diffnormalization;
627
628 if (skyclearness==1)
629 normfactor = 0.777778;
630
631 if (skyclearness>=6)
632 {
633 F2 = 0.274*(0.91 + 10.0*exp(-3.0*(M_PI/2.0-altitude)) + 0.45*sundir[2]*sundir[2]);
634 normfactor = normsc()/F2/M_PI;
635 }
636
637 if ( (skyclearness>1) && (skyclearness<6) )
638 {
639 S_INTER=1;
640 F2 = (2.739 + .9891*sin(.3119+2.6*altitude)) * exp(-(M_PI/2.0-altitude)*(.4441+1.48*altitude));
641 normfactor = normsc()/F2/M_PI;
642 }
643
644 groundbr = zenithbr*normfactor;
645
646 if (dosun&&(skyclearness>1))
647 groundbr += 6.8e-5/M_PI*solarradiance*sundir[2];
648
649 groundbr *= gprefl;
650
651
652
653 if(*(c_perez+1)>0)
654 {
655 if(suppress_warnings==0)
656 { fprintf(stderr, "Warning: positive Perez parameter B (= %lf), printing error sky\n",*(c_perez+1));}
657 print_error_sky();
658 exit(0);
659 }
660
661
662 return;
663 }
664
665
666
667
668
669 double solar_sunset(int month,int day)
670 {
671 float W;
672 extern double s_latitude;
673 W=-1*(tan(s_latitude)*tan(sdec(jdate(month, day))));
674 return(12+(M_PI/2 - atan2(W,sqrt(1-W*W)))*180/(M_PI*15));
675 }
676
677
678
679
680 double solar_sunrise(int month,int day)
681 {
682 float W;
683 extern double s_latitude;
684 W=-1*(tan(s_latitude)*tan(sdec(jdate(month, day))));
685 return(12-(M_PI/2 - atan2(W,sqrt(1-W*W)))*180/(M_PI*15));
686 }
687
688
689
690
691 void printsky()
692 {
693
694 printf("# Local solar time: %.2f\n", st);
695 printf("# Solar altitude and azimuth: %.1f %.1f\n", altitude*180/M_PI, azimuth*180/M_PI);
696
697
698 if (dosun&&(skyclearness>1))
699 {
700 printf("\nvoid light solar\n");
701 printf("0\n0\n");
702 printf("3 %.3e %.3e %.3e\n", solarradiance, solarradiance, solarradiance);
703 printf("\nsolar source sun\n");
704 printf("0\n0\n");
705 printf("4 %f %f %f %f\n", sundir[0], sundir[1], sundir[2], 2*half_sun_angle);
706 } else if (dosun) {
707 printf("\nvoid light solar\n");
708 printf("0\n0\n");
709 printf("3 0.0 0.0 0.0\n");
710 printf("\nsolar source sun\n");
711 printf("0\n0\n");
712 printf("4 %f %f %f %f\n", sundir[0], sundir[1], sundir[2], 2*half_sun_angle);
713 }
714 /* print colored output if activated in command line (-C). Based on model from A. Diakite, TU-Berlin. Implemented by J. Wienold, August 26 2018 */
715 if (color_output==1 && skyclearness < 4.5 && skyclearness >1.065 )
716 {
717 fprintf(stderr, " warning: sky clearness(epsilon)= %f \n",skyclearness);
718 fprintf(stderr, " warning: intermediate sky!! \n");
719 fprintf(stderr, " warning: color model for intermediate sky pending \n");
720 fprintf(stderr, " warning: no color output ! \n");
721 color_output=0;
722 }
723 if (color_output==1)
724 {
725 printf("\nvoid colorfunc skyfunc\n");
726 printf("4 skybright_r skybright_g skybright_b perezlum_c.cal\n");
727 printf("0\n");
728 printf("22 %.3e %.3e %lf %lf %lf %lf %lf %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f\n", diffnormalization, groundbr,
729 *(c_perez+0),*(c_perez+1),*(c_perez+2),*(c_perez+3),*(c_perez+4),
730 sundir[0], sundir[1], sundir[2],skyclearness,locus[0],locus[1],locus[2],locus[3],locus[4],locus[5],locus[6],locus[7],locus[8],locus[9],locus[10]);
731 }else{
732 printf("\nvoid brightfunc skyfunc\n");
733 printf("2 skybright perezlum.cal\n");
734 printf("0\n");
735 printf("10 %.3e %.3e %lf %lf %lf %lf %lf %f %f %f \n", diffnormalization, groundbr,
736 *(c_perez+0),*(c_perez+1),*(c_perez+2),*(c_perez+3),*(c_perez+4),
737 sundir[0], sundir[1], sundir[2]);
738 }
739
740 }
741
742
743
744 void print_error_sky()
745 {
746
747
748 sundir[0] = -sin(azimuth)*cos(altitude);
749 sundir[1] = -cos(azimuth)*cos(altitude);
750 sundir[2] = sin(altitude);
751
752 printf("# Local solar time: %.2f\n", st);
753 printf("# Solar altitude and azimuth: %.1f %.1f\n", altitude*180/M_PI, azimuth*180/M_PI);
754
755 printf("\nvoid brightfunc skyfunc\n");
756 printf("2 skybright perezlum.cal\n");
757 printf("0\n");
758 printf("10 0.00 0.00 0.000 0.000 0.000 0.000 0.000 %f %f %f \n", sundir[0], sundir[1], sundir[2]);
759 }
760
761
762
763
764
765 void printdefaults() /* print default values */
766 {
767 printf("-g %f\t\t\t# Ground plane reflectance\n", gprefl);
768 if (zenithbr > 0.0)
769 printf("-b %f\t\t\t# Zenith radiance (watts/ster/m^2\n", zenithbr);
770 else
771 printf("-t %f\t\t\t# Atmospheric betaturbidity\n", betaturbidity);
772 printf("-a %f\t\t\t# Site latitude (degrees)\n", s_latitude*(180/M_PI));
773 printf("-o %f\t\t\t# Site longitude (degrees)\n", s_longitude*(180/M_PI));
774 printf("-m %f\t\t\t# Standard meridian (degrees)\n", s_meridian*(180/M_PI));
775 }
776
777
778
779
780 void usage_error(char* msg) /* print usage error and quit */
781 {
782 if (msg != NULL)
783 fprintf(stderr, "%s: Use error - %s\n\n", progname, msg);
784 fprintf(stderr, "Usage: %s month day hour [...]\n", progname);
785 fprintf(stderr, " or: %s -ang altitude azimuth [...]\n", progname);
786 fprintf(stderr, " followed by: -P epsilon delta [options]\n");
787 fprintf(stderr, " or: [-W|-L|-G] direct_value diffuse_value [options]\n");
788 fprintf(stderr, " or: -E global_irradiance [options]\n\n");
789 fprintf(stderr, " Description:\n");
790 fprintf(stderr, " -P epsilon delta (these are the Perez parameters) \n");
791 fprintf(stderr, " -W direct-normal-irradiance diffuse-horizontal-irradiance (W/m^2)\n");
792 fprintf(stderr, " -L direct-normal-illuminance diffuse-horizontal-illuminance (lux)\n");
793 fprintf(stderr, " -G direct-horizontal-irradiance diffuse-horizontal-irradiance (W/m^2)\n");
794 fprintf(stderr, " -E global-horizontal-irradiance (W/m^2)\n\n");
795 fprintf(stderr, " Output specification with option:\n");
796 fprintf(stderr, " -O [0|1|2] (0=output in W/m^2/sr visible, 1=output in W/m^2/sr solar, 2=output in candela/m^2), default is 0 \n");
797 fprintf(stderr, " gendaylit version 2.5 (2018/04/18) \n\n");
798 exit(1);
799 }
800
801
802
803
804 double normsc() /* compute normalization factor (E0*F2/L0) */
805 {
806 static double nfc[2][5] = {
807 /* clear sky approx. */
808 {2.766521, 0.547665, -0.369832, 0.009237, 0.059229},
809 /* intermediate sky approx. */
810 {3.5556, -2.7152, -1.3081, 1.0660, 0.60227},
811 };
812 register double *nf;
813 double x, nsc;
814 register int i;
815 /* polynomial approximation */
816 nf = nfc[S_INTER];
817 x = (altitude - M_PI/4.0)/(M_PI/4.0);
818 nsc = nf[i=4];
819 while (i--)
820 nsc = nsc*x + nf[i];
821
822 return(nsc);
823 }
824
825
826
827
828
829 void printhead(int ac, char** av) /* print command header */
830 {
831 putchar('#');
832 while (ac--) {
833 putchar(' ');
834 fputs(*av++, stdout);
835 }
836 putchar('\n');
837 }
838
839
840
841
842
843
844 /* Perez models */
845
846 /* Perez global horizontal luminous efficacy model */
847 double glob_h_effi_PEREZ()
848 {
849
850 double value;
851 double category_bounds[10], a[10], b[10], c[10], d[10];
852 int category_total_number, category_number, i;
853
854 check_parametrization();
855
856
857 /*if ((skyclearness<skyclearinf || skyclearness>skyclearsup || skybrightness<skybriginf || skybrightness>skybrigsup) && suppress_warnings==0)
858 fprintf(stderr, "Warning: skyclearness or skybrightness out of range in function glob_h_effi_PEREZ \n"); */
859
860
861 /* initialize category bounds (clearness index bounds) */
862
863 category_total_number = 8;
864
865 category_bounds[1] = 1;
866 category_bounds[2] = 1.065;
867 category_bounds[3] = 1.230;
868 category_bounds[4] = 1.500;
869 category_bounds[5] = 1.950;
870 category_bounds[6] = 2.800;
871 category_bounds[7] = 4.500;
872 category_bounds[8] = 6.200;
873 category_bounds[9] = 12.01;
874
875
876 /* initialize model coefficients */
877 a[1] = 96.63;
878 a[2] = 107.54;
879 a[3] = 98.73;
880 a[4] = 92.72;
881 a[5] = 86.73;
882 a[6] = 88.34;
883 a[7] = 78.63;
884 a[8] = 99.65;
885
886 b[1] = -0.47;
887 b[2] = 0.79;
888 b[3] = 0.70;
889 b[4] = 0.56;
890 b[5] = 0.98;
891 b[6] = 1.39;
892 b[7] = 1.47;
893 b[8] = 1.86;
894
895 c[1] = 11.50;
896 c[2] = 1.79;
897 c[3] = 4.40;
898 c[4] = 8.36;
899 c[5] = 7.10;
900 c[6] = 6.06;
901 c[7] = 4.93;
902 c[8] = -4.46;
903
904 d[1] = -9.16;
905 d[2] = -1.19;
906 d[3] = -6.95;
907 d[4] = -8.31;
908 d[5] = -10.94;
909 d[6] = -7.60;
910 d[7] = -11.37;
911 d[8] = -3.15;
912
913
914
915 for (i=1; i<=category_total_number; i++)
916 {
917 if ( (skyclearness >= category_bounds[i]) && (skyclearness < category_bounds[i+1]) )
918 category_number = i;
919 }
920
921 value = a[category_number] + b[category_number]*atm_preci_water +
922 c[category_number]*cos(sunzenith*M_PI/180) + d[category_number]*log(skybrightness);
923
924 return(value);
925 }
926
927
928
929
930 /* global horizontal diffuse efficacy model, according to PEREZ */
931 double glob_h_diffuse_effi_PEREZ()
932 {
933 double value;
934 double category_bounds[10], a[10], b[10], c[10], d[10];
935 int category_total_number, category_number, i;
936
937 check_parametrization();
938
939
940 /*if ((skyclearness<skyclearinf || skyclearness>skyclearsup || skybrightness<skybriginf || skybrightness>skybrigsup) && suppress_warnings==0)
941 fprintf(stderr, "Warning: skyclearness or skybrightness out of range in function glob_h_diffuse_PEREZ \n"); */
942
943 /* initialize category bounds (clearness index bounds) */
944
945 category_total_number = 8;
946
947 //XXX: category_bounds > 0.1
948 category_bounds[1] = 1;
949 category_bounds[2] = 1.065;
950 category_bounds[3] = 1.230;
951 category_bounds[4] = 1.500;
952 category_bounds[5] = 1.950;
953 category_bounds[6] = 2.800;
954 category_bounds[7] = 4.500;
955 category_bounds[8] = 6.200;
956 category_bounds[9] = 12.01;
957
958
959 /* initialize model coefficients */
960 a[1] = 97.24;
961 a[2] = 107.22;
962 a[3] = 104.97;
963 a[4] = 102.39;
964 a[5] = 100.71;
965 a[6] = 106.42;
966 a[7] = 141.88;
967 a[8] = 152.23;
968
969 b[1] = -0.46;
970 b[2] = 1.15;
971 b[3] = 2.96;
972 b[4] = 5.59;
973 b[5] = 5.94;
974 b[6] = 3.83;
975 b[7] = 1.90;
976 b[8] = 0.35;
977
978 c[1] = 12.00;
979 c[2] = 0.59;
980 c[3] = -5.53;
981 c[4] = -13.95;
982 c[5] = -22.75;
983 c[6] = -36.15;
984 c[7] = -53.24;
985 c[8] = -45.27;
986
987 d[1] = -8.91;
988 d[2] = -3.95;
989 d[3] = -8.77;
990 d[4] = -13.90;
991 d[5] = -23.74;
992 d[6] = -28.83;
993 d[7] = -14.03;
994 d[8] = -7.98;
995
996
997
998 category_number = -1;
999 for (i=1; i<=category_total_number; i++)
1000 {
1001 if ( (skyclearness >= category_bounds[i]) && (skyclearness < category_bounds[i+1]) )
1002 category_number = i;
1003 }
1004
1005 if (category_number == -1) {
1006 if (suppress_warnings==0)
1007 fprintf(stderr, "Warning: sky clearness (= %.3f) too high, printing error sky\n", skyclearness);
1008 print_error_sky();
1009 exit(0);
1010 }
1011
1012
1013 value = a[category_number] + b[category_number]*atm_preci_water + c[category_number]*cos(sunzenith*M_PI/180) +
1014 d[category_number]*log(skybrightness);
1015
1016 return(value);
1017
1018 }
1019
1020
1021
1022
1023
1024
1025 /* direct normal efficacy model, according to PEREZ */
1026
1027 double direct_n_effi_PEREZ()
1028
1029 {
1030 double value;
1031 double category_bounds[10], a[10], b[10], c[10], d[10];
1032 int category_total_number, category_number, i;
1033
1034
1035 /*if ((skyclearness<skyclearinf || skyclearness>skyclearsup || skybrightness<skybriginf || skybrightness>skybrigsup) && suppress_warnings==0)
1036 fprintf(stderr, "Warning: skyclearness or skybrightness out of range in function direct_n_effi_PEREZ \n");*/
1037
1038
1039 /* initialize category bounds (clearness index bounds) */
1040
1041 category_total_number = 8;
1042
1043 category_bounds[1] = 1;
1044 category_bounds[2] = 1.065;
1045 category_bounds[3] = 1.230;
1046 category_bounds[4] = 1.500;
1047 category_bounds[5] = 1.950;
1048 category_bounds[6] = 2.800;
1049 category_bounds[7] = 4.500;
1050 category_bounds[8] = 6.200;
1051 category_bounds[9] = 12.1;
1052
1053
1054 /* initialize model coefficients */
1055 a[1] = 57.20;
1056 a[2] = 98.99;
1057 a[3] = 109.83;
1058 a[4] = 110.34;
1059 a[5] = 106.36;
1060 a[6] = 107.19;
1061 a[7] = 105.75;
1062 a[8] = 101.18;
1063
1064 b[1] = -4.55;
1065 b[2] = -3.46;
1066 b[3] = -4.90;
1067 b[4] = -5.84;
1068 b[5] = -3.97;
1069 b[6] = -1.25;
1070 b[7] = 0.77;
1071 b[8] = 1.58;
1072
1073 c[1] = -2.98;
1074 c[2] = -1.21;
1075 c[3] = -1.71;
1076 c[4] = -1.99;
1077 c[5] = -1.75;
1078 c[6] = -1.51;
1079 c[7] = -1.26;
1080 c[8] = -1.10;
1081
1082 d[1] = 117.12;
1083 d[2] = 12.38;
1084 d[3] = -8.81;
1085 d[4] = -4.56;
1086 d[5] = -6.16;
1087 d[6] = -26.73;
1088 d[7] = -34.44;
1089 d[8] = -8.29;
1090
1091
1092
1093 for (i=1; i<=category_total_number; i++)
1094 {
1095 if ( (skyclearness >= category_bounds[i]) && (skyclearness < category_bounds[i+1]) )
1096 category_number = i;
1097 }
1098
1099 value = a[category_number] + b[category_number]*atm_preci_water + c[category_number]*exp(5.73*sunzenith*M_PI/180 - 5) + d[category_number]*skybrightness;
1100
1101 if (value < 0) value = 0;
1102
1103 return(value);
1104 }
1105
1106
1107 /*check the range of epsilon and delta indexes of the perez parametrization*/
1108 void check_parametrization()
1109 {
1110
1111 if (skyclearness<skyclearinf || skyclearness>skyclearsup || skybrightness<skybriginf || skybrightness>skybrigsup)
1112 {
1113
1114 /* limit sky clearness or sky brightness, 2009 11 13 by J. Wienold */
1115
1116 if (skyclearness<skyclearinf){
1117 /* if (suppress_warnings==0)
1118 fprintf(stderr,"Range warning: sky clearness too low (%lf)\n", skyclearness); */
1119 skyclearness=skyclearinf;
1120 }
1121 if (skyclearness>skyclearsup){
1122 /* if (suppress_warnings==0)
1123 fprintf(stderr,"Range warning: sky clearness too high (%lf)\n", skyclearness); */
1124 skyclearness=skyclearsup-0.001;
1125 }
1126 if (skybrightness<skybriginf){
1127 /* if (suppress_warnings==0)
1128 fprintf(stderr,"Range warning: sky brightness too low (%lf)\n", skybrightness); */
1129 skybrightness=skybriginf;
1130 }
1131 if (skybrightness>skybrigsup){
1132 /* if (suppress_warnings==0)
1133 fprintf(stderr,"Range warning: sky brightness too high (%lf)\n", skybrightness); */
1134 skybrightness=skybrigsup;
1135 }
1136
1137 return; }
1138 else return;
1139 }
1140
1141
1142
1143
1144
1145 /* validity of the direct and diffuse components */
1146 void check_illuminances()
1147 {
1148 if (directilluminance < 0) {
1149 if(suppress_warnings==0)
1150 { fprintf(stderr,"Warning: direct illuminance < 0. Using 0.0\n"); }
1151 directilluminance = 0.0;
1152 }
1153 if (diffuseilluminance < 0) {
1154 if(suppress_warnings==0)
1155 { fprintf(stderr,"Warning: diffuse illuminance < 0. Using 0.0\n"); }
1156 diffuseilluminance = 0.0;
1157 }
1158
1159 if (directilluminance+diffuseilluminance==0 && altitude > 0) {
1160 if(suppress_warnings==0)
1161 { fprintf(stderr,"Warning: zero illuminance at sun altitude > 0, printing error sky\n"); }
1162 print_error_sky();
1163 exit(0);
1164 }
1165
1166 if (directilluminance > solar_constant_l) {
1167 if(suppress_warnings==0)
1168 { fprintf(stderr,"Warning: direct illuminance exceeds solar constant\n"); }
1169 print_error_sky();
1170 exit(0);
1171 }
1172 }
1173
1174
1175 void check_irradiances()
1176 {
1177 if (directirradiance < 0) {
1178 if(suppress_warnings==0)
1179 { fprintf(stderr,"Warning: direct irradiance < 0. Using 0.0\n"); }
1180 directirradiance = 0.0;
1181 }
1182 if (diffuseirradiance < 0) {
1183 if(suppress_warnings==0)
1184 { fprintf(stderr,"Warning: diffuse irradiance < 0. Using 0.0\n"); }
1185 diffuseirradiance = 0.0;
1186 }
1187
1188 if (directirradiance+diffuseirradiance==0 && altitude > 0) {
1189 if(suppress_warnings==0)
1190 { fprintf(stderr,"Warning: zero irradiance at sun altitude > 0, printing error sky\n"); }
1191 print_error_sky();
1192 exit(0);
1193 }
1194
1195 if (directirradiance > solar_constant_e) {
1196 if(suppress_warnings==0)
1197 { fprintf(stderr,"Warning: direct irradiance exceeds solar constant\n"); }
1198 print_error_sky();
1199 exit(0);
1200 }
1201 }
1202
1203
1204
1205 /* Perez sky's brightness */
1206 double sky_brightness()
1207 {
1208 double value;
1209
1210 value = diffuseirradiance * air_mass() / ( solar_constant_e*get_eccentricity());
1211
1212 return(value);
1213 }
1214
1215
1216 /* Perez sky's clearness */
1217 double sky_clearness()
1218 {
1219 double value;
1220
1221 value = ( (diffuseirradiance + directirradiance)/(diffuseirradiance) + 1.041*sunzenith*M_PI/180*sunzenith*M_PI/180*sunzenith*M_PI/180 ) / (1 + 1.041*sunzenith*M_PI/180*sunzenith*M_PI/180*sunzenith*M_PI/180) ;
1222
1223 return(value);
1224 }
1225
1226
1227
1228 /* diffus horizontal irradiance from Perez sky's brightness */
1229 double diffuse_irradiance_from_sky_brightness()
1230 {
1231 double value;
1232
1233 value = skybrightness / air_mass() * ( solar_constant_e*get_eccentricity());
1234
1235 return(value);
1236 }
1237
1238
1239 /* direct normal irradiance from Perez sky's clearness */
1240 double direct_irradiance_from_sky_clearness()
1241 {
1242 double value;
1243
1244 value = diffuse_irradiance_from_sky_brightness();
1245 value = value * ( (skyclearness-1) * (1+1.041*sunzenith*M_PI/180*sunzenith*M_PI/180*sunzenith*M_PI/180) );
1246
1247 return(value);
1248 }
1249
1250
1251
1252
1253 void illu_to_irra_index()
1254 {
1255 double test1=0.1, test2=0.1, d_eff;
1256 int counter=0;
1257
1258 diffuseirradiance = diffuseilluminance*solar_constant_e/(solar_constant_l);
1259 directirradiance = directilluminance*solar_constant_e/(solar_constant_l);
1260 skyclearness = sky_clearness();
1261 skybrightness = sky_brightness();
1262 check_parametrization();
1263
1264
1265 while ( ((fabs(diffuseirradiance-test1)>10) || (fabs(directirradiance-test2)>10)
1266 || (!(skyclearness<skyclearinf || skyclearness>skyclearsup))
1267 || (!(skybrightness<skybriginf || skybrightness>skybrigsup)) )
1268 && !(counter==9) )
1269 {
1270
1271 test1=diffuseirradiance;
1272 test2=directirradiance;
1273 counter++;
1274
1275 diffuseirradiance = diffuseilluminance/glob_h_diffuse_effi_PEREZ();
1276 d_eff = direct_n_effi_PEREZ();
1277
1278
1279 if (d_eff < 0.1)
1280 directirradiance = 0;
1281 else
1282 directirradiance = directilluminance/d_eff;
1283
1284 skybrightness = sky_brightness();
1285 skyclearness = sky_clearness();
1286 check_parametrization();
1287
1288 }
1289
1290
1291 return;
1292 }
1293
1294 static int get_numlin(float epsilon)
1295 {
1296 if (epsilon < 1.065)
1297 return 0;
1298 else if (epsilon < 1.230)
1299 return 1;
1300 else if (epsilon < 1.500)
1301 return 2;
1302 else if (epsilon < 1.950)
1303 return 3;
1304 else if (epsilon < 2.800)
1305 return 4;
1306 else if (epsilon < 4.500)
1307 return 5;
1308 else if (epsilon < 6.200)
1309 return 6;
1310 return 7;
1311 }
1312
1313 /* sky luminance perez model */
1314 double calc_rel_lum_perez(double dzeta,double gamma,double Z,double epsilon,double Delta,float coeff_perez[])
1315 {
1316
1317 float x[5][4];
1318 int i,j,num_lin;
1319 double c_perez[5];
1320
1321 if ( (epsilon < skyclearinf) || (epsilon >= skyclearsup) )
1322 {
1323 fprintf(stderr,"Error: epsilon out of range in function calc_rel_lum_perez!\n");
1324 exit(1);
1325 }
1326
1327 /* correction de modele de Perez solar energy ...*/
1328 if ( (epsilon > 1.065) && (epsilon < 2.8) )
1329 {
1330 if ( Delta < 0.2 ) Delta = 0.2;
1331 }
1332
1333
1334 num_lin = get_numlin(epsilon);
1335
1336 for (i=0;i<5;i++)
1337 for (j=0;j<4;j++)
1338 {
1339 x[i][j] = *(coeff_perez + 20*num_lin + 4*i +j);
1340 /* fprintf(stderr,"x %d %d vaut %f\n",i,j,x[i][j]); */
1341 }
1342
1343
1344 if (num_lin)
1345 {
1346 for (i=0;i<5;i++)
1347 c_perez[i] = x[i][0] + x[i][1]*Z + Delta * (x[i][2] + x[i][3]*Z);
1348 }
1349 else
1350 {
1351 c_perez[0] = x[0][0] + x[0][1]*Z + Delta * (x[0][2] + x[0][3]*Z);
1352 c_perez[1] = x[1][0] + x[1][1]*Z + Delta * (x[1][2] + x[1][3]*Z);
1353 c_perez[4] = x[4][0] + x[4][1]*Z + Delta * (x[4][2] + x[4][3]*Z);
1354 c_perez[2] = exp( pow(Delta*(x[2][0]+x[2][1]*Z),x[2][2])) - x[2][3];
1355 c_perez[3] = -exp( Delta*(x[3][0]+x[3][1]*Z) )+x[3][2]+Delta*x[3][3];
1356 }
1357
1358
1359 return (1 + c_perez[0]*exp(c_perez[1]/cos(dzeta)) ) *
1360 (1 + c_perez[2]*exp(c_perez[3]*gamma) +
1361 c_perez[4]*cos(gamma)*cos(gamma) );
1362 }
1363
1364
1365
1366 /* coefficients for the sky luminance perez model */
1367 void coeff_lum_perez(double Z, double epsilon, double Delta, float coeff_perez[])
1368 {
1369 float x[5][4];
1370 int i,j,num_lin;
1371
1372 if ( (epsilon < skyclearinf) || (epsilon >= skyclearsup) )
1373 {
1374 fprintf(stderr,"Error: epsilon out of range in function coeff_lum_perez!\n");
1375 exit(1);
1376 }
1377
1378 /* correction du modele de Perez solar energy ...*/
1379 if ( (epsilon > 1.065) && (epsilon < 2.8) )
1380 {
1381 if ( Delta < 0.2 ) Delta = 0.2;
1382 }
1383
1384
1385 num_lin = get_numlin(epsilon);
1386
1387 /*fprintf(stderr,"numlin %d\n", num_lin);*/
1388
1389 for (i=0;i<5;i++)
1390 for (j=0;j<4;j++)
1391 {
1392 x[i][j] = *(coeff_perez + 20*num_lin + 4*i +j);
1393 /* printf("x %d %d vaut %f\n",i,j,x[i][j]); */
1394 }
1395
1396
1397 if (num_lin)
1398 {
1399 for (i=0;i<5;i++)
1400 *(c_perez+i) = x[i][0] + x[i][1]*Z + Delta * (x[i][2] + x[i][3]*Z);
1401
1402 }
1403 else
1404 {
1405 *(c_perez+0) = x[0][0] + x[0][1]*Z + Delta * (x[0][2] + x[0][3]*Z);
1406 *(c_perez+1) = x[1][0] + x[1][1]*Z + Delta * (x[1][2] + x[1][3]*Z);
1407 *(c_perez+4) = x[4][0] + x[4][1]*Z + Delta * (x[4][2] + x[4][3]*Z);
1408 *(c_perez+2) = exp( pow(Delta*(x[2][0]+x[2][1]*Z),x[2][2])) - x[2][3];
1409 *(c_perez+3) = -exp( Delta*(x[3][0]+x[3][1]*Z) )+x[3][2]+Delta*x[3][3];
1410
1411
1412 }
1413
1414
1415 return;
1416 }
1417
1418
1419
1420 /* degrees into radians */
1421 double radians(double degres)
1422 {
1423 return degres*M_PI/180.0;
1424 }
1425
1426
1427 /* radian into degrees */
1428 double degres(double radians)
1429 {
1430 return radians/M_PI*180.0;
1431 }
1432
1433
1434 /* calculation of the angles dzeta and gamma */
1435 void theta_phi_to_dzeta_gamma(double theta,double phi,double *dzeta,double *gamma, double Z)
1436 {
1437 *dzeta = theta; /* dzeta = phi */
1438 if ( (cos(Z)*cos(theta)+sin(Z)*sin(theta)*cos(phi)) > 1 && (cos(Z)*cos(theta)+sin(Z)*sin(theta)*cos(phi) < 1.1 ) )
1439 *gamma = 0;
1440 else if ( (cos(Z)*cos(theta)+sin(Z)*sin(theta)*cos(phi)) > 1.1 )
1441 {
1442 printf("error in calculation of gamma (angle between point and sun");
1443 exit(1);
1444 }
1445 else
1446 *gamma = acos(cos(Z)*cos(theta)+sin(Z)*sin(theta)*cos(phi));
1447 }
1448
1449
1450
1451 double integ_lv(float *lv,float *theta)
1452 {
1453 int i;
1454 double buffer=0.0;
1455
1456 for (i=0;i<145;i++)
1457 {
1458 buffer += (*(lv+i))*cos(radians(*(theta+i)));
1459 }
1460
1461 return buffer*2*M_PI/144;
1462 }
1463
1464
1465
1466 /* enter day number(double), return E0 = square(R0/R): eccentricity correction factor */
1467
1468 double get_eccentricity()
1469 {
1470 double day_angle;
1471 double E0;
1472
1473 day_angle = 2*M_PI*(daynumber - 1)/365;
1474 E0 = 1.00011+0.034221*cos(day_angle)+0.00128*sin(day_angle)+
1475 0.000719*cos(2*day_angle)+0.000077*sin(2*day_angle);
1476
1477 return (E0);
1478 }
1479
1480
1481 /* enter sunzenith angle (degrees) return relative air mass (double) */
1482 double air_mass()
1483 {
1484 double m;
1485 if (sunzenith>90)
1486 {
1487 if(suppress_warnings==0)
1488 { fprintf(stderr, "Warning: air mass has reached the maximal value\n"); }
1489 sunzenith=90;
1490 }
1491 m = 1/( cos(sunzenith*M_PI/180)+0.15*exp( log(93.885-sunzenith)*(-1.253) ) );
1492 return(m);
1493 }
1494
1495
1496

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