39 |
|
/* default values */ |
40 |
|
int cloudy = 0; /* 1=standard, 2=uniform */ |
41 |
|
int dosun = 1; |
42 |
< |
double zenithbr = -1.0; |
42 |
> |
double zenithbr = 0.0; |
43 |
> |
int u_zenith = 0; /* -1=irradiance, 1=radiance */ |
44 |
|
double turbidity = 2.75; |
45 |
|
double gprefl = 0.2; |
46 |
|
/* computed values */ |
47 |
|
double sundir[3]; |
48 |
|
double groundbr; |
49 |
|
double F2; |
50 |
< |
double solarbr = -1.0; |
50 |
> |
double solarbr = 0.0; |
51 |
> |
int u_solar = 0; /* -1=irradiance, 1=radiance */ |
52 |
|
|
53 |
|
char *progname; |
54 |
|
char errmsg[128]; |
91 |
|
dosun = argv[i][0] == '+'; |
92 |
|
break; |
93 |
|
case 'r': |
94 |
+ |
case 'R': |
95 |
+ |
u_solar = argv[i][1]=='R' ? -1 : 1; |
96 |
|
solarbr = atof(argv[++i]); |
97 |
|
break; |
98 |
|
case 'c': |
103 |
|
turbidity = atof(argv[++i]); |
104 |
|
break; |
105 |
|
case 'b': |
106 |
+ |
case 'B': |
107 |
+ |
u_zenith = argv[i][1]=='B' ? -1 : 1; |
108 |
|
zenithbr = atof(argv[++i]); |
109 |
|
break; |
110 |
|
case 'g': |
140 |
|
|
141 |
|
computesky() /* compute sky parameters */ |
142 |
|
{ |
143 |
+ |
double normfactor; |
144 |
|
/* compute solar direction */ |
145 |
|
if (month) { /* from date and time */ |
146 |
|
int jd; |
169 |
|
sundir[1] = -cos(azimuth)*cos(altitude); |
170 |
|
sundir[2] = sin(altitude); |
171 |
|
|
172 |
+ |
/* Compute normalization factor */ |
173 |
+ |
if (cloudy == 2) |
174 |
+ |
normfactor = 1.0; |
175 |
+ |
else if (cloudy == 1) |
176 |
+ |
normfactor = 0.777778; |
177 |
+ |
else { |
178 |
+ |
F2 = 0.274*(0.91 + 10.0*exp(-3.0*(PI/2.0-altitude)) + |
179 |
+ |
0.45*sundir[2]*sundir[2]); |
180 |
+ |
normfactor = normsc(altitude)/F2/PI; |
181 |
+ |
} |
182 |
|
/* Compute zenith brightness */ |
183 |
< |
if (zenithbr <= 0.0) |
184 |
< |
if (cloudy) { |
183 |
> |
if (u_zenith == -1) |
184 |
> |
zenithbr /= normfactor*PI; |
185 |
> |
else if (u_zenith == 0) { |
186 |
> |
if (cloudy) |
187 |
|
zenithbr = 8.6*sundir[2] + .123; |
188 |
< |
zenithbr *= 1000.0/WHTEFFICACY; |
170 |
< |
} else { |
188 |
> |
else |
189 |
|
zenithbr = (1.376*turbidity-1.81)*tan(altitude)+0.38; |
190 |
< |
zenithbr *= 1000.0/SKYEFFICACY; |
191 |
< |
} |
174 |
< |
if (zenithbr < 0.0) |
175 |
< |
zenithbr = 0.0; |
176 |
< |
/* Compute horizontal radiance */ |
177 |
< |
if (cloudy) { |
178 |
< |
if (cloudy == 2) |
179 |
< |
groundbr = zenithbr; |
190 |
> |
if (zenithbr < 0.0) |
191 |
> |
zenithbr = 0.0; |
192 |
|
else |
193 |
< |
groundbr = zenithbr*0.777778; |
182 |
< |
printf("# Ground ambient level: %f\n", groundbr); |
183 |
< |
} else { |
184 |
< |
F2 = 0.274*(0.91 + 10.0*exp(-3.0*(PI/2.0-altitude)) + |
185 |
< |
0.45*sundir[2]*sundir[2]); |
186 |
< |
groundbr = zenithbr*normsc(altitude)/F2/PI; |
187 |
< |
printf("# Ground ambient level: %f\n", groundbr); |
188 |
< |
if (sundir[2] > 0.0 && solarbr != 0.0) { |
189 |
< |
if (solarbr < 0.0) |
190 |
< |
solarbr = 1.5e9/SUNEFFICACY * |
191 |
< |
(1.147 - .147/(sundir[2]>.16?sundir[2]:.16)); |
192 |
< |
groundbr += solarbr*6e-5*sundir[2]/PI; |
193 |
< |
} else |
194 |
< |
dosun = 0; |
193 |
> |
zenithbr *= 1000.0/SKYEFFICACY; |
194 |
|
} |
195 |
+ |
/* Compute horizontal radiance */ |
196 |
+ |
groundbr = zenithbr*normfactor; |
197 |
+ |
printf("# Ground ambient level: %f\n", groundbr); |
198 |
+ |
if (sundir[2] > 0.0 && (!u_solar || solarbr > 0.0)) { |
199 |
+ |
if (u_solar == -1) |
200 |
+ |
solarbr /= 6e-5*sundir[2]; |
201 |
+ |
else if (u_solar == 0) |
202 |
+ |
solarbr = 1.5e9/SUNEFFICACY * |
203 |
+ |
(1.147 - .147/(sundir[2]>.16?sundir[2]:.16)); |
204 |
+ |
groundbr += 6e-5/PI*solarbr*sundir[2]; |
205 |
+ |
} else |
206 |
+ |
dosun = 0; |
207 |
|
groundbr *= gprefl; |
208 |
|
} |
209 |
|
|