2389:
743:
553:
1146:
962:
In astronomy, stars are routinely treated as point sources even though they are much larger than the Earth. This is a good approximation because the distance from even a nearby star to the Earth is much larger than the star's diameter. For instance, the irradiance of
409:
319:
195:
738:{\displaystyle E_{\mathrm {e} }={\frac {n}{2\mu _{0}\mathrm {c} }}E_{\mathrm {m} }^{2}\cos \alpha ={\frac {n\varepsilon _{0}\mathrm {c} }{2}}E_{\mathrm {m} }^{2}\cos \alpha ={\frac {n}{2Z_{0}}}E_{\mathrm {m} }^{2}\cos \alpha ,}
500:
923:
1026:
2053:
per unit frequency or wavelength. The latter is commonly measured in W⋅m⋅nm. "Spectral emittance" is an old term for this quantity. This is sometimes also confusingly called "spectral intensity".
106:(W⋅m⋅Hz), while spectral irradiance of a wavelength spectrum is measured in watts per square metre per metre (W⋅m), or more commonly watts per square metre per nanometre (W⋅m⋅nm).
959:
For quick approximations, this equation indicates that doubling the distance reduces irradiation to one quarter; or similarly, to double irradiation, reduce the distance to 0.7.
2011:
per unit area. This is the emitted component of radiosity. "Radiant emittance" is an old term for this quantity. This is sometimes also confusingly called "intensity".
344:
254:
136:
1166:
Average solar irradiance at the top of the Earth's atmosphere is roughly 1361 W/m, but at surface irradiance is approximately 1000 W/m on a clear day.
1013:, which is the component that is reflected from the ground. The average ground reflection is about 20% of the global irradiance. Hence, the irradiance
440:
547:, the Poynting vector always points to the direction of propagation while oscillating in magnitude. The irradiance of a surface is then given by
1787:
per unit frequency or wavelength. This is sometimes also confusingly called "spectral intensity". Non-SI units of spectral flux density include
2521:
58:
1934:
per unit frequency or wavelength. The latter is commonly measured in W⋅m⋅nm. This is sometimes also confusingly called "spectral intensity".
1198:
2604:
Liu, B. Y. H.; Jordan, R. C. (1960). "The interrelationship and characteristic distribution of direct, diffuse and total solar radiation".
857:
of light produces spherical wavefronts. The irradiance in this case varies inversely with the square of the distance from the source.
1358:
Radiant energy emitted, reflected, transmitted or received, per unit time. This is sometimes also called "radiant power", and called
1141:{\displaystyle E_{\mathrm {e} }=E_{\mathrm {e} ,\mathrm {dir} }+E_{\mathrm {e} ,\mathrm {diff} }+E_{\mathrm {e} ,\mathrm {refl} }.}
863:
2172:
per unit frequency or wavelength. The latter is commonly measured in J⋅m⋅nm. This is sometimes also called "spectral fluence".
2484:
2559:
2513:
1191:
17:
95:
50:
2645:
1184:
1531:
Radiant intensity per unit frequency or wavelength. The latter is commonly measured in W⋅sr⋅nm. This is a
2582:
2454:
820:
812:
404:{\displaystyle E_{\mathrm {e} ,\lambda }={\frac {\partial E_{\mathrm {e} }}{\partial \lambda }},}
102:
and units: spectral irradiance of a frequency spectrum is measured in watts per square metre per
2244:
1897:
1854:
1282:
2449:
1750:
838:
2613:
2251:
should be denoted with suffix "e" (for "energetic") to avoid confusion with photometric or
99:
1656:
per unit frequency or wavelength. The latter is commonly measured in W⋅sr⋅m⋅nm. This is a
1485:
Radiant flux emitted, reflected, transmitted or received, per unit solid angle. This is a
841:
of the propagation medium. This assumption is typically valid in transparent media in the
8:
2650:
2434:
2225:
992:
The global irradiance on a horizontal surface on Earth consists of the direct irradiance
801:
790:
540:
314:{\displaystyle E_{\mathrm {e} ,\nu }={\frac {\partial E_{\mathrm {e} }}{\partial \nu }},}
127:
69:
2617:
1408:
Radiant flux per unit frequency or wavelength. The latter is commonly measured in W⋅nm.
2544:
2514:"Thermal insulation — Heat transfer by radiation — Physical quantities and definitions"
205:
2130:
integrated over time of irradiation. This is sometimes also called "radiant fluence".
2625:
2578:
2555:
2490:
2480:
2248:
1617:
1494:
1445:
525:
190:{\displaystyle E_{\mathrm {e} }={\frac {\partial \Phi _{\mathrm {e} }}{\partial A}},}
73:
2621:
2439:
2135:
2092:
2016:
1973:
1156:
987:
968:
964:
842:
765:
230:
98:
is taken as a function of frequency or of wavelength. The two forms have different
72:, but this term is avoided in radiometry where such usage leads to confusion with
2423:
1800:
431:
1239:
775:
2388:
2639:
2551:
2494:
495:{\displaystyle E_{\mathrm {e} }=\langle |\mathbf {S} |\rangle \cos \alpha ,}
2333:, not to be confused with a letter "v", indicating a photometric quantity.)
1703:
1367:
1321:
942:
854:
427:
39:
1660:
quantity. This is sometimes also confusingly called "spectral intensity".
2413:
2330:
2444:
2418:
2356:
2220:
1359:
1160:
975:
544:
91:
31:
1892:
per unit area. This is sometimes also confusingly called "intensity".
1741:
per unit area. This is sometimes also confusingly called "intensity".
2320:
2269:
2267:
2265:
2263:
2261:
1467:
1461:
87:
65:
2428:
1574:
1152:
2258:
2550:(3. ed., reprint. with corr. ed.). Upper Saddle River, NJ :
2408:
1612:
quantity. This is sometimes also confusingly called "intensity".
426:
Irradiance of a surface is also, according to the definition of
2403:
2252:
1788:
779:
1604:
Radiant flux emitted, reflected, transmitted or received by a
1390:
1384:
1259:
1254:
103:
64:
per square centimetre per second (erg⋅cm⋅s) is often used in
1006:. On a tilted plane, there is another irradiance component,
1339:
1334:
918:{\displaystyle E={\frac {P}{A}}={\frac {P}{4\pi r^{2}}}.\,}
54:
2378:
2361:
2325:
1608:, per unit solid angle per unit projected area. This is a
61:
331:
Spectral irradiance in wavelength of a surface, denoted
2583:"Technology fundamentals—The sun as an energy resource"
2215:
241:
Spectral irradiance in frequency of a surface, denoted
1029:
866:
556:
443:
347:
257:
139:
2392:
Comparison of photometric and radiometric quantities
2373:
2371:
2351:
2349:
2347:
2345:
2343:
2341:
2339:
430:, equal to the time-average of the component of the
2543:
1155:of solar irradiance over a time period is called "
1140:
917:
737:
494:
403:
313:
189:
2368:
2336:
2637:
2377:Directional quantities are denoted with suffix "
2315:
2313:
2311:
2309:
2307:
2305:
2303:
1020:on a tilted plane consists of three components:
2508:
2506:
2504:
2126:per unit area, or equivalently irradiance of a
1678:watt per steradian per square metre, per metre
1637:watt per steradian per square metre per hertz
758:is the amplitude of the wave's electric field;
126:("e" for "energetic", to avoid confusion with
2300:
1192:
2573:
2571:
2501:
2238:
477:
459:
109:
27:Measure of radiant energy over surface area
2577:
1888:(emitted, reflected and transmitted by) a
1199:
1185:
951:is the surface area of a sphere of radius
225:If we want to talk about the radiant flux
2603:
2568:
2541:
914:
2535:
2387:
86:is the irradiance of a surface per unit
76:. In astrophysics, irradiance is called
2474:
14:
2638:
2477:An introduction to modern astrophysics
1169:
236:
2134:
2015:
1896:
1745:
1616:
1493:
1366:
1277:Energy of electromagnetic radiation.
1219:
1216:
1213:
1210:
2273:Alternative symbols sometimes seen:
1589:watt per steradian per square metre
2355:Spectral quantities given per unit
2319:Spectral quantities given per unit
981:
524:is the angle between a unit vector
24:
2475:Carroll, Bradley W. (2017-09-07).
2190:joule per square metre, per metre
1129:
1126:
1123:
1120:
1112:
1097:
1094:
1091:
1088:
1080:
1065:
1062:
1059:
1051:
1036:
978:) is about 2.7 × 10 W/m on Earth.
712:
661:
645:
605:
592:
563:
450:
389:
381:
372:
354:
299:
291:
282:
264:
175:
167:
162:
158:
146:
25:
2662:
2431:(photosynthesis-irradiance curve)
2153:joule per square metre per hertz
2071:watt per square metre, per metre
1952:watt per square metre, per metre
1833:watt per square metre, per metre
119:Irradiance of a surface, denoted
2034:watt per square metre per hertz
1915:watt per square metre per hertz
1768:watt per square metre per hertz
1316:Radiant energy per unit volume.
468:
2546:Introduction to electrodynamics
848:
2597:
2468:
819:This formula assumes that the
473:
463:
434:perpendicular to the surface:
13:
1:
2461:
2122:Radiant energy received by a
1553:watt per steradian per metre
1512:watt per steradian per hertz
768:of the medium of propagation;
215:is the radiant flux received;
114:
68:. Irradiance is often called
2626:10.1016/0038-092X(60)90062-1
2542:Griffiths, David J. (1999).
57:per square metre (W⋅m). The
7:
2396:
2247:recommend that radiometric
421:
130:quantities), is defined as
94:, depending on whether the
10:
2667:
985:
229:by a surface, we speak of
2359:are denoted with suffix "
2323:are denoted with suffix "
2210:
2167:
2091:
2048:
1972:
1929:
1853:
1782:
1698:
1651:
1573:
1530:
1444:
1407:
1320:
1281:
1238:
1233:
1230:
1227:
1224:
823:is negligible; i.e. that
110:Mathematical definitions
2245:Standards organizations
2107:joule per square metre
999:and diffuse irradiance
843:optical frequency range
821:magnetic susceptibility
813:impedance of free space
518:is the Poynting vector;
2587:Renewable Energy World
2393:
2168:Radiant exposure of a
2049:Radiant exitance of a
1988:watt per square metre
1869:watt per square metre
1718:watt per square metre
1297:joule per cubic metre
1283:Radiant energy density
1142:
919:
739:
496:
405:
315:
191:
2450:Spectral flux density
2391:
2297:for radiant exitance.
1751:Spectral flux density
1143:
920:
839:magnetic permeability
740:
497:
406:
316:
192:
53:of irradiance is the
2455:Stefan–Boltzmann law
2281:for radiant energy,
1027:
864:
554:
512:is the time-average;
441:
345:
255:
137:
49:per unit area. The
2646:Physical quantities
2618:1960SoEn....4....1L
2435:Solar azimuth angle
1747:Spectral irradiance
1621:Specific intensity
1207:
1179:SI radiometry units
1170:SI radiometry units
967:(radiant flux: 1.5
802:vacuum permittivity
791:vacuum permeability
722:
671:
615:
528:to the surface and
418:is the wavelength.
237:Spectral irradiance
84:Spectral irradiance
2579:Quaschning, Volker
2394:
2289:for radiant flux,
1898:Spectral radiosity
1495:Spectral intensity
1176:
1138:
915:
735:
706:
655:
599:
541:linearly polarized
536:For a propagating
492:
401:
328:is the frequency.
311:
206:partial derivative
187:
2486:978-1-108-42216-1
2234:
2233:
2136:Spectral exposure
2017:Spectral exitance
1618:Spectral radiance
1446:Radiant intensity
974:, distance: 4.34
909:
881:
704:
653:
597:
396:
306:
182:
74:radiant intensity
16:(Redirected from
2658:
2630:
2629:
2601:
2595:
2594:
2575:
2566:
2565:
2549:
2539:
2533:
2532:
2530:
2529:
2510:
2499:
2498:
2472:
2440:Solar irradiance
2382:
2375:
2366:
2353:
2334:
2329:" (Greek letter
2317:
2298:
2296:
2293:for irradiance,
2292:
2288:
2284:
2280:
2276:
2271:
2256:
2242:
2187:
2150:
2104:
2093:Radiant exposure
2068:
2031:
1985:
1974:Radiant exitance
1949:
1912:
1866:
1830:
1814:
1810:
1806:
1798:
1794:
1783:Irradiance of a
1765:
1715:
1675:
1634:
1586:
1550:
1509:
1457:
1421:
1380:
1331:
1294:
1251:
1208:
1201:
1194:
1187:
1180:
1175:
1147:
1145:
1144:
1139:
1134:
1133:
1132:
1115:
1102:
1101:
1100:
1083:
1070:
1069:
1068:
1054:
1041:
1040:
1039:
988:Solar irradiance
982:Solar irradiance
965:Alpha Centauri A
954:
950:
940:
935:is the distance;
934:
924:
922:
921:
916:
910:
908:
907:
906:
887:
882:
874:
766:refractive index
744:
742:
741:
736:
721:
716:
715:
705:
703:
702:
701:
685:
670:
665:
664:
654:
649:
648:
643:
642:
629:
614:
609:
608:
598:
596:
595:
590:
589:
573:
568:
567:
566:
543:electromagnetic
511:
501:
499:
498:
493:
476:
471:
466:
455:
454:
453:
410:
408:
407:
402:
397:
395:
387:
386:
385:
384:
370:
365:
364:
357:
338:, is defined as
320:
318:
317:
312:
307:
305:
297:
296:
295:
294:
280:
275:
274:
267:
248:, is defined as
231:radiant exitance
196:
194:
193:
188:
183:
181:
173:
172:
171:
170:
156:
151:
150:
149:
21:
2666:
2665:
2661:
2660:
2659:
2657:
2656:
2655:
2636:
2635:
2634:
2633:
2602:
2598:
2576:
2569:
2562:
2540:
2536:
2527:
2525:
2524:catalogue. 1989
2512:
2511:
2502:
2487:
2473:
2469:
2464:
2459:
2424:Light diffusion
2399:
2386:
2385:
2376:
2369:
2354:
2337:
2318:
2301:
2294:
2290:
2286:
2282:
2278:
2274:
2272:
2259:
2243:
2239:
2230:
2186:
2177:
2149:
2140:
2103:
2097:
2067:
2058:
2030:
2021:
1984:
1978:
1948:
1939:
1930:Radiosity of a
1911:
1902:
1865:
1859:
1829:
1820:
1812:
1808:
1804:
1801:solar flux unit
1796:
1792:
1764:
1755:
1749:
1714:
1708:
1702:
1674:
1665:
1633:
1624:
1620:
1585:
1579:
1549:
1540:
1508:
1499:
1456:
1450:
1424:watt per metre
1420:
1413:
1379:
1372:
1330:
1326:
1293:
1287:
1250:
1244:
1206:
1205:
1178:
1172:
1119:
1111:
1110:
1106:
1087:
1079:
1078:
1074:
1058:
1050:
1049:
1045:
1035:
1034:
1030:
1028:
1025:
1024:
1019:
1012:
1005:
998:
990:
984:
972:
952:
948:
938:
932:
902:
898:
891:
886:
873:
865:
862:
861:
851:
836:
829:
810:
799:
788:
757:
717:
711:
710:
697:
693:
689:
684:
666:
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659:
644:
638:
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630:
628:
610:
604:
603:
591:
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581:
577:
572:
562:
561:
557:
555:
552:
551:
509:
472:
467:
462:
449:
448:
444:
442:
439:
438:
432:Poynting vector
424:
388:
380:
379:
375:
371:
369:
353:
352:
348:
346:
343:
342:
337:
298:
290:
289:
285:
281:
279:
263:
262:
258:
256:
253:
252:
247:
239:
214:
174:
166:
165:
161:
157:
155:
145:
144:
140:
138:
135:
134:
125:
117:
112:
28:
23:
22:
15:
12:
11:
5:
2664:
2654:
2653:
2648:
2632:
2631:
2596:
2567:
2560:
2534:
2500:
2485:
2479:. p. 60.
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2465:
2463:
2460:
2458:
2457:
2452:
2447:
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2432:
2426:
2421:
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2411:
2406:
2400:
2398:
2395:
2384:
2383:
2367:
2335:
2299:
2257:
2236:
2235:
2232:
2231:
2229:
2228:
2223:
2218:
2212:
2208:
2207:
2194:
2191:
2188:
2181:
2174:
2173:
2166:
2157:
2154:
2151:
2144:
2138:
2132:
2131:
2120:
2111:
2108:
2105:
2101:
2095:
2089:
2088:
2075:
2072:
2069:
2062:
2055:
2054:
2047:
2038:
2035:
2032:
2025:
2019:
2013:
2012:
2001:
1992:
1989:
1986:
1982:
1976:
1970:
1969:
1956:
1953:
1950:
1943:
1936:
1935:
1928:
1919:
1916:
1913:
1906:
1900:
1894:
1893:
1882:
1873:
1870:
1867:
1863:
1857:
1851:
1850:
1837:
1834:
1831:
1824:
1817:
1816:
1809:10 W⋅m⋅Hz
1797:10 W⋅m⋅Hz
1781:
1772:
1769:
1766:
1759:
1753:
1743:
1742:
1731:
1722:
1719:
1716:
1712:
1706:
1696:
1695:
1682:
1679:
1676:
1669:
1662:
1661:
1652:Radiance of a
1650:
1641:
1638:
1635:
1628:
1622:
1614:
1613:
1602:
1593:
1590:
1587:
1583:
1577:
1571:
1570:
1557:
1554:
1551:
1544:
1537:
1536:
1529:
1516:
1513:
1510:
1503:
1497:
1491:
1490:
1483:
1470:
1464:
1458:
1454:
1448:
1442:
1441:
1428:
1425:
1422:
1415:
1410:
1409:
1406:
1393:
1387:
1381:
1374:
1370:
1364:
1363:
1362:in Astronomy.
1356:
1343:
1337:
1332:
1328:
1324:
1318:
1317:
1314:
1301:
1298:
1295:
1291:
1285:
1279:
1278:
1275:
1262:
1257:
1252:
1248:
1242:
1240:Radiant energy
1236:
1235:
1232:
1229:
1226:
1222:
1221:
1218:
1215:
1212:
1204:
1203:
1196:
1189:
1181:
1177:
1171:
1168:
1157:solar exposure
1149:
1148:
1137:
1131:
1128:
1125:
1122:
1118:
1114:
1109:
1105:
1099:
1096:
1093:
1090:
1086:
1082:
1077:
1073:
1067:
1064:
1061:
1057:
1053:
1048:
1044:
1038:
1033:
1017:
1010:
1003:
996:
986:Main article:
983:
980:
970:
957:
956:
946:
936:
926:
925:
913:
905:
901:
897:
894:
890:
885:
880:
877:
872:
869:
850:
847:
834:
827:
817:
816:
808:
805:
797:
794:
786:
783:
776:speed of light
769:
759:
755:
746:
745:
734:
731:
728:
725:
720:
714:
709:
700:
696:
692:
688:
683:
680:
677:
674:
669:
663:
658:
652:
647:
641:
637:
633:
627:
624:
621:
618:
613:
607:
602:
594:
588:
584:
580:
576:
571:
565:
560:
534:
533:
519:
513:
503:
502:
491:
488:
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458:
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447:
423:
420:
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411:
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394:
391:
383:
378:
374:
368:
363:
360:
356:
351:
335:
322:
321:
310:
304:
301:
293:
288:
284:
278:
273:
270:
266:
261:
245:
238:
235:
223:
222:
216:
212:
209:
198:
197:
186:
180:
177:
169:
164:
160:
154:
148:
143:
123:
116:
113:
111:
108:
26:
18:Radiation flux
9:
6:
4:
3:
2:
2663:
2652:
2649:
2647:
2644:
2643:
2641:
2627:
2623:
2619:
2615:
2611:
2607:
2600:
2592:
2588:
2584:
2580:
2574:
2572:
2563:
2561:0-13-805326-X
2557:
2553:
2552:Prentice-Hall
2548:
2547:
2538:
2523:
2519:
2518:ISO 9288:1989
2515:
2509:
2507:
2505:
2496:
2492:
2488:
2482:
2478:
2471:
2467:
2456:
2453:
2451:
2448:
2446:
2443:
2441:
2438:
2436:
2433:
2430:
2427:
2425:
2422:
2420:
2417:
2415:
2412:
2410:
2407:
2405:
2402:
2401:
2390:
2380:
2374:
2372:
2364:
2363:
2358:
2352:
2350:
2348:
2346:
2344:
2342:
2340:
2332:
2328:
2327:
2322:
2316:
2314:
2312:
2310:
2308:
2306:
2304:
2270:
2268:
2266:
2264:
2262:
2254:
2250:
2246:
2241:
2237:
2227:
2224:
2222:
2219:
2217:
2214:
2213:
2209:
2206:
2202:
2198:
2195:
2192:
2189:
2185:
2180:
2176:
2175:
2171:
2165:
2161:
2158:
2155:
2152:
2148:
2143:
2139:
2137:
2133:
2129:
2125:
2121:
2119:
2115:
2112:
2109:
2106:
2100:
2096:
2094:
2090:
2087:
2083:
2079:
2076:
2073:
2070:
2066:
2061:
2057:
2056:
2052:
2046:
2042:
2039:
2036:
2033:
2029:
2024:
2020:
2018:
2014:
2010:
2006:
2003:Radiant flux
2002:
2000:
1996:
1993:
1990:
1987:
1981:
1977:
1975:
1971:
1968:
1964:
1960:
1957:
1954:
1951:
1947:
1942:
1938:
1937:
1933:
1927:
1923:
1920:
1917:
1914:
1910:
1905:
1901:
1899:
1895:
1891:
1887:
1884:Radiant flux
1883:
1881:
1877:
1874:
1871:
1868:
1862:
1858:
1856:
1852:
1849:
1845:
1841:
1838:
1835:
1832:
1828:
1823:
1819:
1818:
1802:
1790:
1786:
1780:
1776:
1773:
1770:
1767:
1763:
1758:
1754:
1752:
1748:
1744:
1740:
1736:
1733:Radiant flux
1732:
1730:
1726:
1723:
1720:
1717:
1711:
1707:
1705:
1701:
1697:
1694:
1690:
1686:
1683:
1680:
1677:
1673:
1668:
1664:
1663:
1659:
1655:
1649:
1645:
1642:
1639:
1636:
1632:
1627:
1623:
1619:
1615:
1611:
1607:
1603:
1601:
1597:
1594:
1591:
1588:
1582:
1578:
1576:
1572:
1569:
1565:
1561:
1558:
1555:
1552:
1548:
1543:
1539:
1538:
1534:
1528:
1524:
1520:
1517:
1514:
1511:
1507:
1502:
1498:
1496:
1492:
1488:
1484:
1482:
1478:
1474:
1471:
1469:
1465:
1463:
1459:
1453:
1449:
1447:
1443:
1440:
1436:
1432:
1429:
1426:
1423:
1419:
1412:
1411:
1405:
1401:
1397:
1394:
1392:
1388:
1386:
1382:
1378:
1371:
1369:
1368:Spectral flux
1365:
1361:
1357:
1355:
1351:
1347:
1344:
1341:
1338:
1336:
1333:
1325:
1323:
1319:
1315:
1313:
1309:
1305:
1302:
1299:
1296:
1290:
1286:
1284:
1280:
1276:
1274:
1270:
1266:
1263:
1261:
1258:
1256:
1253:
1247:
1243:
1241:
1237:
1223:
1209:
1202:
1197:
1195:
1190:
1188:
1183:
1182:
1174:
1167:
1164:
1162:
1158:
1154:
1135:
1116:
1107:
1103:
1084:
1075:
1071:
1055:
1046:
1042:
1031:
1023:
1022:
1021:
1016:
1009:
1002:
995:
989:
979:
977:
973:
966:
960:
947:
944:
937:
931:
930:
929:
911:
903:
899:
895:
892:
888:
883:
878:
875:
870:
867:
860:
859:
858:
856:
846:
844:
840:
833:
826:
822:
814:
806:
803:
795:
792:
784:
781:
777:
773:
770:
767:
763:
760:
754:
751:
750:
749:
732:
729:
726:
723:
718:
707:
698:
694:
690:
686:
681:
678:
675:
672:
667:
656:
650:
639:
635:
631:
625:
622:
619:
616:
611:
600:
586:
582:
578:
574:
569:
558:
550:
549:
548:
546:
542:
539:
531:
527:
523:
520:
517:
514:
508:
507:
506:
489:
486:
483:
480:
456:
445:
437:
436:
435:
433:
429:
419:
417:
398:
392:
376:
366:
361:
358:
349:
341:
340:
339:
334:
329:
327:
308:
302:
286:
276:
271:
268:
259:
251:
250:
249:
244:
234:
232:
228:
220:
217:
210:
207:
203:
202:
201:
184:
178:
152:
141:
133:
132:
131:
129:
122:
107:
105:
101:
97:
93:
89:
85:
81:
79:
75:
71:
67:
63:
60:
56:
52:
48:
44:
41:
37:
33:
19:
2609:
2606:Solar Energy
2605:
2599:
2590:
2586:
2545:
2537:
2526:. Retrieved
2517:
2476:
2470:
2360:
2324:
2240:
2204:
2200:
2196:
2183:
2178:
2169:
2163:
2159:
2146:
2141:
2127:
2123:
2117:
2113:
2098:
2085:
2081:
2077:
2064:
2059:
2050:
2044:
2040:
2027:
2022:
2008:
2004:
1998:
1994:
1979:
1966:
1962:
1958:
1945:
1940:
1931:
1925:
1921:
1908:
1903:
1889:
1885:
1879:
1875:
1860:
1847:
1843:
1839:
1826:
1821:
1784:
1778:
1774:
1761:
1756:
1746:
1738:
1734:
1728:
1724:
1709:
1704:Flux density
1699:
1692:
1688:
1684:
1671:
1666:
1657:
1653:
1647:
1643:
1630:
1625:
1609:
1605:
1599:
1595:
1580:
1567:
1563:
1559:
1546:
1541:
1532:
1526:
1522:
1518:
1505:
1500:
1486:
1480:
1476:
1472:
1451:
1438:
1434:
1430:
1417:
1403:
1399:
1395:
1376:
1353:
1349:
1345:
1322:Radiant flux
1311:
1307:
1303:
1288:
1272:
1268:
1264:
1245:
1173:
1165:
1150:
1014:
1007:
1000:
993:
991:
961:
958:
943:radiant flux
927:
855:point source
852:
849:Point source
831:
824:
818:
771:
761:
752:
747:
537:
535:
529:
521:
515:
504:
428:radiant flux
425:
415:
413:
332:
330:
325:
323:
242:
240:
226:
224:
221:is the area.
218:
199:
120:
118:
83:
82:
78:radiant flux
77:
46:
42:
40:radiant flux
35:
29:
2593:(5): 90–93.
2414:Illuminance
2255:quantities.
1658:directional
1610:directional
1533:directional
1487:directional
128:photometric
2651:Radiometry
2640:Categories
2528:2015-03-15
2462:References
2445:Solar noon
2419:Insolation
2357:wavelength
2249:quantities
2226:Photometry
2221:Radiometry
2211:See also:
1813:10 Jy
1805:1 sfu
1700:Irradiance
1640:W⋅sr⋅m⋅Hz
1535:quantity.
1489:quantity.
1360:luminosity
1217:Dimension
1161:insolation
830:≈ 1 where
545:plane wave
538:sinusoidal
115:Irradiance
100:dimensions
92:wavelength
36:irradiance
32:radiometry
2495:991641816
2321:frequency
1855:Radiosity
1793:1 Jy
1462:steradian
1460:watt per
1383:watt per
1211:Quantity
896:π
730:α
727:
679:α
676:
636:ε
623:α
620:
583:μ
487:α
484:
478:⟩
460:⟨
393:λ
390:∂
373:∂
362:λ
303:ν
300:∂
283:∂
272:ν
204:∂ is the
176:∂
163:Φ
159:∂
88:frequency
70:intensity
66:astronomy
2612:(3): 1.
2581:(2003).
2429:PI curve
2397:See also
1735:received
1575:Radiance
1515:W⋅sr⋅Hz
1153:integral
422:Property
96:spectrum
59:CGS unit
43:received
2614:Bibcode
2409:Fluence
2170:surface
2156:J⋅m⋅Hz
2128:surface
2124:surface
2051:surface
2037:W⋅m⋅Hz
2009:surface
2005:emitted
1932:surface
1918:W⋅m⋅Hz
1890:surface
1886:leaving
1785:surface
1771:W⋅m⋅Hz
1739:surface
1681:W⋅sr⋅m
1654:surface
1606:surface
1592:W⋅sr⋅m
1556:W⋅sr⋅m
1234:Symbol
1228:Symbol
941:is the
837:is the
811:is the
800:is the
789:is the
774:is the
764:is the
227:emitted
208:symbol;
51:SI unit
47:surface
38:is the
2558:
2493:
2483:
2404:Albedo
2253:photon
1799:) and
1789:jansky
1342:= J/s
1220:Notes
1159:" or "
1011:e,refl
1004:e,diff
928:where
780:vacuum
748:where
526:normal
505:where
414:where
324:where
200:where
2007:by a
1737:by a
1385:hertz
1255:joule
1231:Name
1225:Name
1214:Unit
997:e,dir
510:⟨ • ⟩
104:hertz
45:by a
2556:ISBN
2491:OCLC
2481:ISBN
2193:J/m
2110:J/m
2074:W/m
1991:W/m
1955:W/m
1872:W/m
1836:W/m
1721:W/m
1670:e,Ω,
1629:e,Ω,
1545:e,Ω,
1504:e,Ω,
1427:W/m
1335:watt
1300:J/m
1151:The
55:watt
2622:doi
2522:ISO
2285:or
2277:or
1815:).
1584:e,Ω
1455:e,Ω
1163:".
778:in
724:cos
673:cos
617:cos
481:cos
336:e,λ
246:e,ν
90:or
62:erg
30:In
2642::
2620:.
2608:.
2589:.
2585:.
2570:^
2554:.
2520:.
2516:.
2503:^
2489:.
2381:".
2370:^
2365:".
2338:^
2331:nu
2302:^
2260:^
2216:SI
2182:e,
2145:e,
2063:e,
2026:e,
1944:e,
1907:e,
1825:e,
1811:=
1807:=
1795:=
1760:e,
1468:sr
1466:W/
1416:e,
1391:Hz
1389:W/
1375:e,
976:ly
853:A
845:.
233:.
80:.
34:,
2628:.
2624::
2616::
2610:4
2591:6
2564:.
2531:.
2497:.
2379:Ω
2362:λ
2326:ν
2295:W
2291:I
2287:F
2283:P
2279:E
2275:W
2205:T
2203:⋅
2201:L
2199:⋅
2197:M
2184:λ
2179:H
2164:T
2162:⋅
2160:M
2147:ν
2142:H
2118:T
2116:⋅
2114:M
2102:e
2099:H
2086:T
2084:⋅
2082:L
2080:⋅
2078:M
2065:λ
2060:M
2045:T
2043:⋅
2041:M
2028:ν
2023:M
1999:T
1997:⋅
1995:M
1983:e
1980:M
1967:T
1965:⋅
1963:L
1961:⋅
1959:M
1946:λ
1941:J
1926:T
1924:⋅
1922:M
1909:ν
1904:J
1880:T
1878:⋅
1876:M
1864:e
1861:J
1848:T
1846:⋅
1844:L
1842:⋅
1840:M
1827:λ
1822:E
1803:(
1791:(
1779:T
1777:⋅
1775:M
1762:ν
1757:E
1729:T
1727:⋅
1725:M
1713:e
1710:E
1693:T
1691:⋅
1689:L
1687:⋅
1685:M
1672:λ
1667:L
1648:T
1646:⋅
1644:M
1631:ν
1626:L
1600:T
1598:⋅
1596:M
1581:L
1568:T
1566:⋅
1564:L
1562:⋅
1560:M
1547:λ
1542:I
1527:T
1525:⋅
1523:L
1521:⋅
1519:M
1506:ν
1501:I
1481:T
1479:⋅
1477:L
1475:⋅
1473:M
1452:I
1439:T
1437:⋅
1435:L
1433:⋅
1431:M
1418:λ
1414:Φ
1404:T
1402:⋅
1400:L
1398:⋅
1396:M
1377:ν
1373:Φ
1354:T
1352:⋅
1350:L
1348:⋅
1346:M
1340:W
1329:e
1327:Φ
1312:T
1310:⋅
1308:L
1306:⋅
1304:M
1292:e
1289:w
1273:T
1271:⋅
1269:L
1267:⋅
1265:M
1260:J
1249:e
1246:Q
1200:e
1193:t
1186:v
1136:.
1130:l
1127:f
1124:e
1121:r
1117:,
1113:e
1108:E
1104:+
1098:f
1095:f
1092:i
1089:d
1085:,
1081:e
1076:E
1072:+
1066:r
1063:i
1060:d
1056:,
1052:e
1047:E
1043:=
1037:e
1032:E
1018:e
1015:E
1008:E
1001:E
994:E
971:☉
969:L
955:.
953:r
949:A
945:;
939:P
933:r
912:.
904:2
900:r
893:4
889:P
884:=
879:A
876:P
871:=
868:E
835:r
832:μ
828:r
825:μ
815:.
809:0
807:Z
804:;
798:0
796:ε
793:;
787:0
785:μ
782:;
772:c
762:n
756:m
753:E
733:,
719:2
713:m
708:E
699:0
695:Z
691:2
687:n
682:=
668:2
662:m
657:E
651:2
646:c
640:0
632:n
626:=
612:2
606:m
601:E
593:c
587:0
579:2
575:n
570:=
564:e
559:E
532:.
530:S
522:α
516:S
490:,
474:|
469:S
464:|
457:=
451:e
446:E
416:λ
399:,
382:e
377:E
367:=
359:,
355:e
350:E
333:E
326:ν
309:,
292:e
287:E
277:=
269:,
265:e
260:E
243:E
219:A
213:e
211:Φ
185:,
179:A
168:e
153:=
147:e
142:E
124:e
121:E
20:)
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