26 |
|
|
27 |
|
#define DOT(v1,v2) (v1[0]*v2[0]+v1[1]*v2[1]+v1[2]*v2[2]) |
28 |
|
|
29 |
+ |
#define S_CLEAR 1 |
30 |
+ |
#define S_OVER 2 |
31 |
+ |
#define S_UNIF 3 |
32 |
+ |
#define S_INTER 4 |
33 |
+ |
|
34 |
+ |
#define overcast (skytype==S_OVER|skytype==S_UNIF) |
35 |
+ |
|
36 |
|
double normsc(); |
37 |
|
/* sun calculation constants */ |
38 |
|
extern double s_latitude; |
44 |
|
int tsolar; /* 0=standard, 1=solar */ |
45 |
|
double altitude, azimuth; /* or solar angles */ |
46 |
|
/* default values */ |
47 |
< |
int cloudy = 0; /* 1=standard, 2=uniform */ |
47 |
> |
int skytype = S_CLEAR; /* sky type */ |
48 |
|
int dosun = 1; |
49 |
|
double zenithbr = 0.0; |
50 |
|
int u_zenith = 0; /* -1=irradiance, 1=radiance */ |
94 |
|
if (argv[i][0] == '-' || argv[i][0] == '+') |
95 |
|
switch (argv[i][1]) { |
96 |
|
case 's': |
97 |
< |
cloudy = 0; |
97 |
> |
skytype = S_CLEAR; |
98 |
|
dosun = argv[i][0] == '+'; |
99 |
|
break; |
100 |
|
case 'r': |
103 |
|
solarbr = atof(argv[++i]); |
104 |
|
break; |
105 |
|
case 'c': |
106 |
< |
cloudy = argv[i][0] == '+' ? 2 : 1; |
100 |
< |
dosun = 0; |
106 |
> |
skytype = S_OVER; |
107 |
|
break; |
108 |
+ |
case 'u': |
109 |
+ |
skytype = S_UNIF; |
110 |
+ |
break; |
111 |
+ |
case 'i': |
112 |
+ |
skytype = S_INTER; |
113 |
+ |
dosun = argv[i][0] == '+'; |
114 |
+ |
break; |
115 |
|
case 't': |
116 |
|
turbidity = atof(argv[++i]); |
117 |
|
break; |
148 |
|
|
149 |
|
computesky(); |
150 |
|
printsky(); |
151 |
+ |
|
152 |
+ |
exit(0); |
153 |
|
} |
154 |
|
|
155 |
|
|
169 |
|
st = hour + stadj(jd); |
170 |
|
altitude = salt(sd, st); |
171 |
|
azimuth = sazi(sd, st); |
172 |
< |
printf("# Solar altitude and azimuth: %f %f\n", |
172 |
> |
printf("# Solar altitude and azimuth: %.1f %.1f\n", |
173 |
|
180./PI*altitude, 180./PI*azimuth); |
174 |
|
} |
175 |
< |
if (!cloudy && altitude > 87.*PI/180.) { |
175 |
> |
if (!overcast && altitude > 87.*PI/180.) { |
176 |
|
fprintf(stderr, |
177 |
|
"%s: warning - sun too close to zenith, reducing altitude to 87 degrees\n", |
178 |
|
progname); |
185 |
|
sundir[2] = sin(altitude); |
186 |
|
|
187 |
|
/* Compute normalization factor */ |
188 |
< |
if (cloudy == 2) |
188 |
> |
switch (skytype) { |
189 |
> |
case S_UNIF: |
190 |
|
normfactor = 1.0; |
191 |
< |
else if (cloudy == 1) |
191 |
> |
break; |
192 |
> |
case S_OVER: |
193 |
|
normfactor = 0.777778; |
194 |
< |
else { |
194 |
> |
break; |
195 |
> |
case S_CLEAR: |
196 |
|
F2 = 0.274*(0.91 + 10.0*exp(-3.0*(PI/2.0-altitude)) + |
197 |
|
0.45*sundir[2]*sundir[2]); |
198 |
< |
normfactor = normsc(altitude)/F2/PI; |
198 |
> |
normfactor = normsc()/F2/PI; |
199 |
> |
break; |
200 |
> |
case S_INTER: |
201 |
> |
F2 = (2.739 + .9891*sin(.3119+2.6*altitude)) * |
202 |
> |
exp(-(PI/2.0-altitude)*(.4441+1.48*altitude)); |
203 |
> |
normfactor = normsc()/F2/PI; |
204 |
> |
break; |
205 |
|
} |
206 |
|
/* Compute zenith brightness */ |
207 |
|
if (u_zenith == -1) |
208 |
|
zenithbr /= normfactor*PI; |
209 |
|
else if (u_zenith == 0) { |
210 |
< |
if (cloudy) |
210 |
> |
if (overcast) |
211 |
|
zenithbr = 8.6*sundir[2] + .123; |
212 |
|
else |
213 |
|
zenithbr = (1.376*turbidity-1.81)*tan(altitude)+0.38; |
214 |
+ |
if (skytype == S_INTER) |
215 |
+ |
zenithbr = (zenithbr + 8.6*sundir[2] + .123)/2.0; |
216 |
|
if (zenithbr < 0.0) |
217 |
|
zenithbr = 0.0; |
218 |
|
else |
220 |
|
} |
221 |
|
/* Compute horizontal radiance */ |
222 |
|
groundbr = zenithbr*normfactor; |
223 |
< |
printf("# Ground ambient level: %f\n", groundbr); |
224 |
< |
if (sundir[2] > 0.0 && (!u_solar || solarbr > 0.0)) { |
223 |
> |
printf("# Ground ambient level: %.1f\n", groundbr); |
224 |
> |
if (!overcast && sundir[2] > 0.0 && (!u_solar || solarbr > 0.0)) { |
225 |
|
if (u_solar == -1) |
226 |
|
solarbr /= 6e-5*sundir[2]; |
227 |
< |
else if (u_solar == 0) |
227 |
> |
else if (u_solar == 0) { |
228 |
|
solarbr = 1.5e9/SUNEFFICACY * |
229 |
|
(1.147 - .147/(sundir[2]>.16?sundir[2]:.16)); |
230 |
+ |
if (skytype == S_INTER) |
231 |
+ |
solarbr *= 0.15; /* fudge factor! */ |
232 |
+ |
} |
233 |
|
groundbr += 6e-5/PI*solarbr*sundir[2]; |
234 |
|
} else |
235 |
|
dosun = 0; |
249 |
|
} |
250 |
|
|
251 |
|
printf("\nvoid brightfunc skyfunc\n"); |
252 |
< |
printf("2 skybright skybright.cal\n"); |
252 |
> |
printf("2 skybr skybright.cal\n"); |
253 |
|
printf("0\n"); |
254 |
< |
if (cloudy) |
255 |
< |
printf("3 %d %.2e %.2e\n", cloudy, zenithbr, groundbr); |
254 |
> |
if (overcast) |
255 |
> |
printf("3 %d %.2e %.2e\n", skytype, zenithbr, groundbr); |
256 |
|
else |
257 |
< |
printf("7 -1 %.2e %.2e %.2e %f %f %f\n", zenithbr, groundbr, |
258 |
< |
F2, sundir[0], sundir[1], sundir[2]); |
257 |
> |
printf("7 %d %.2e %.2e %.2e %f %f %f\n", |
258 |
> |
skytype, zenithbr, groundbr, F2, |
259 |
> |
sundir[0], sundir[1], sundir[2]); |
260 |
|
} |
261 |
|
|
262 |
|
|
263 |
|
printdefaults() /* print default values */ |
264 |
|
{ |
265 |
< |
if (cloudy == 1) |
265 |
> |
switch (skytype) { |
266 |
> |
case S_OVER: |
267 |
|
printf("-c\t\t\t\t# Cloudy sky\n"); |
268 |
< |
else if (cloudy == 2) |
269 |
< |
printf("+c\t\t\t\t# Uniform cloudy sky\n"); |
270 |
< |
else if (dosun) |
271 |
< |
printf("+s\t\t\t\t# Sunny sky with sun\n"); |
272 |
< |
else |
273 |
< |
printf("-s\t\t\t\t# Sunny sky without sun\n"); |
268 |
> |
break; |
269 |
> |
case S_UNIF: |
270 |
> |
printf("-u\t\t\t\t# Uniform cloudy sky\n"); |
271 |
> |
break; |
272 |
> |
case S_INTER: |
273 |
> |
if (dosun) |
274 |
> |
printf("+i\t\t\t\t# Intermediate sky with sun\n"); |
275 |
> |
else |
276 |
> |
printf("-i\t\t\t\t# Intermediate sky without sun\n"); |
277 |
> |
break; |
278 |
> |
case S_CLEAR: |
279 |
> |
if (dosun) |
280 |
> |
printf("+s\t\t\t\t# Sunny sky with sun\n"); |
281 |
> |
else |
282 |
> |
printf("-s\t\t\t\t# Sunny sky without sun\n"); |
283 |
> |
break; |
284 |
> |
} |
285 |
|
printf("-g %f\t\t\t# Ground plane reflectance\n", gprefl); |
286 |
|
if (zenithbr > 0.0) |
287 |
|
printf("-b %f\t\t\t# Zenith radiance (watts/ster/m2\n", zenithbr); |
306 |
|
|
307 |
|
|
308 |
|
double |
309 |
< |
normsc(theta) /* compute normalization factor (E0*F2/L0) */ |
268 |
< |
double theta; |
309 |
> |
normsc() /* compute normalization factor (E0*F2/L0) */ |
310 |
|
{ |
311 |
< |
static double nf[5] = {2.766521, 0.547665, |
312 |
< |
-0.369832, 0.009237, 0.059229}; |
311 |
> |
static double nfc[2][5] = { |
312 |
> |
/* clear sky approx. */ |
313 |
> |
{2.766521, 0.547665, -0.369832, 0.009237, 0.059229}, |
314 |
> |
/* intermediate sky approx. */ |
315 |
> |
{3.5556, -2.7152, -1.3081, 1.0660, 0.60227}, |
316 |
> |
}; |
317 |
> |
register double *nf; |
318 |
|
double x, nsc; |
319 |
|
register int i; |
320 |
|
/* polynomial approximation */ |
321 |
< |
x = (theta - PI/4.0)/(PI/4.0); |
322 |
< |
nsc = nf[4]; |
323 |
< |
for (i = 3; i >= 0; i--) |
321 |
> |
nf = nfc[skytype==S_INTER]; |
322 |
> |
x = (altitude - PI/4.0)/(PI/4.0); |
323 |
> |
nsc = nf[i=4]; |
324 |
> |
while (i--) |
325 |
|
nsc = nsc*x + nf[i]; |
326 |
|
|
327 |
|
return(nsc); |