2378:
732:
542:
1135:
951:
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
398:
308:
184:
727:{\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 ,}
489:
912:
1015:
2042:
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".
95:(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).
948:
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.
2000:
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".
333:
243:
125:
1155:
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.
1002:, which is the component that is reflected from the ground. The average ground reflection is about 20% of the global irradiance. Hence, the irradiance
429:
536:, the Poynting vector always points to the direction of propagation while oscillating in magnitude. The irradiance of a surface is then given by
1776:
per unit frequency or wavelength. This is sometimes also confusingly called "spectral intensity". Non-SI units of spectral flux density include
2510:
47:
1923:
per unit frequency or wavelength. The latter is commonly measured in W⋅m⋅nm. This is sometimes also confusingly called "spectral intensity".
1187:
2593:
Liu, B. Y. H.; Jordan, R. C. (1960). "The interrelationship and characteristic distribution of direct, diffuse and total solar radiation".
846:
of light produces spherical wavefronts. The irradiance in this case varies inversely with the square of the distance from the source.
1347:
Radiant energy emitted, reflected, transmitted or received, per unit time. This is sometimes also called "radiant power", and called
1130:{\displaystyle E_{\mathrm {e} }=E_{\mathrm {e} ,\mathrm {dir} }+E_{\mathrm {e} ,\mathrm {diff} }+E_{\mathrm {e} ,\mathrm {refl} }.}
852:
2161:
per unit frequency or wavelength. The latter is commonly measured in J⋅m⋅nm. This is sometimes also called "spectral fluence".
2473:
2548:
2502:
1180:
84:
39:
2634:
1173:
1520:
Radiant intensity per unit frequency or wavelength. The latter is commonly measured in W⋅sr⋅nm. This is a
2571:
2443:
809:
801:
393:{\displaystyle E_{\mathrm {e} ,\lambda }={\frac {\partial E_{\mathrm {e} }}{\partial \lambda }},}
91:
and units: spectral irradiance of a frequency spectrum is measured in watts per square metre per
2233:
1886:
1843:
1271:
2438:
1739:
827:
2602:
2240:
should be denoted with suffix "e" (for "energetic") to avoid confusion with photometric or
88:
1645:
per unit frequency or wavelength. The latter is commonly measured in W⋅sr⋅m⋅nm. This is a
1474:
Radiant flux emitted, reflected, transmitted or received, per unit solid angle. This is a
830:
of the propagation medium. This assumption is typically valid in transparent media in the
8:
2639:
2423:
2214:
981:
The global irradiance on a horizontal surface on Earth consists of the direct irradiance
790:
779:
529:
303:{\displaystyle E_{\mathrm {e} ,\nu }={\frac {\partial E_{\mathrm {e} }}{\partial \nu }},}
116:
58:
2606:
1397:
Radiant flux per unit frequency or wavelength. The latter is commonly measured in W⋅nm.
2533:
2503:"Thermal insulation — Heat transfer by radiation — Physical quantities and definitions"
194:
2119:
integrated over time of irradiation. This is sometimes also called "radiant fluence".
2614:
2567:
2544:
2479:
2469:
2237:
1606:
1483:
1434:
514:
179:{\displaystyle E_{\mathrm {e} }={\frac {\partial \Phi _{\mathrm {e} }}{\partial A}},}
62:
2610:
2428:
2124:
2081:
2005:
1962:
1145:
976:
957:
953:
831:
754:
219:
87:
is taken as a function of frequency or of wavelength. The two forms have different
61:, but this term is avoided in radiometry where such usage leads to confusion with
2412:
1789:
420:
1228:
764:
2377:
2628:
2540:
2483:
484:{\displaystyle E_{\mathrm {e} }=\langle |\mathbf {S} |\rangle \cos \alpha ,}
2322:, not to be confused with a letter "v", indicating a photometric quantity.)
1692:
1356:
1310:
931:
843:
416:
28:
1649:
quantity. This is sometimes also confusingly called "spectral intensity".
2402:
2319:
2433:
2407:
2345:
2209:
1348:
1149:
964:
533:
80:
20:
1881:
per unit area. This is sometimes also confusingly called "intensity".
1730:
per unit area. This is sometimes also confusingly called "intensity".
2309:
2258:
2256:
2254:
2252:
2250:
1456:
1450:
76:
54:
2417:
1563:
1141:
2247:
2539:(3. ed., reprint. with corr. ed.). Upper Saddle River, NJ :
2397:
1601:
quantity. This is sometimes also confusingly called "intensity".
415:
Irradiance of a surface is also, according to the definition of
2392:
2241:
1777:
768:
1593:
Radiant flux emitted, reflected, transmitted or received by a
1379:
1373:
1248:
1243:
92:
53:
per square centimetre per second (erg⋅cm⋅s) is often used in
995:. On a tilted plane, there is another irradiance component,
1328:
1323:
907:{\displaystyle E={\frac {P}{A}}={\frac {P}{4\pi r^{2}}}.\,}
43:
2367:
2350:
2314:
1597:, per unit solid angle per unit projected area. This is a
50:
320:
Spectral irradiance in wavelength of a surface, denoted
2572:"Technology fundamentals—The sun as an energy resource"
2204:
230:
Spectral irradiance in frequency of a surface, denoted
1018:
855:
545:
432:
336:
246:
128:
2381:
Comparison of photometric and radiometric quantities
2362:
2360:
2340:
2338:
2336:
2334:
2332:
2330:
2328:
419:, equal to the time-average of the component of the
2532:
1144:of solar irradiance over a time period is called "
1129:
906:
726:
483:
392:
302:
178:
2357:
2325:
2626:
2366:Directional quantities are denoted with suffix "
2304:
2302:
2300:
2298:
2296:
2294:
2292:
1009:on a tilted plane consists of three components:
2497:
2495:
2493:
2115:per unit area, or equivalently irradiance of a
1667:watt per steradian per square metre, per metre
1626:watt per steradian per square metre per hertz
747:is the amplitude of the wave's electric field;
115:("e" for "energetic", to avoid confusion with
2289:
1181:
2562:
2560:
2490:
2227:
466:
448:
98:
16:Measure of radiant energy over surface area
2566:
1877:(emitted, reflected and transmitted by) a
1188:
1174:
940:is the surface area of a sphere of radius
214:If we want to talk about the radiant flux
2592:
2557:
2530:
903:
2524:
2376:
75:is the irradiance of a surface per unit
65:. In astrophysics, irradiance is called
2463:
2627:
2466:An introduction to modern astrophysics
1158:
225:
2123:
2004:
1885:
1734:
1605:
1482:
1355:
1266:Energy of electromagnetic radiation.
1208:
1205:
1202:
1199:
2262:Alternative symbols sometimes seen:
1578:watt per steradian per square metre
2344:Spectral quantities given per unit
2308:Spectral quantities given per unit
970:
513:is the angle between a unit vector
13:
2464:Carroll, Bradley W. (2017-09-07).
2179:joule per square metre, per metre
1118:
1115:
1112:
1109:
1101:
1086:
1083:
1080:
1077:
1069:
1054:
1051:
1048:
1040:
1025:
967:) is about 2.7 × 10 W/m on Earth.
701:
650:
634:
594:
581:
552:
439:
378:
370:
361:
343:
288:
280:
271:
253:
164:
156:
151:
147:
135:
14:
2651:
2420:(photosynthesis-irradiance curve)
2142:joule per square metre per hertz
2060:watt per square metre, per metre
1941:watt per square metre, per metre
1822:watt per square metre, per metre
108:Irradiance of a surface, denoted
2023:watt per square metre per hertz
1904:watt per square metre per hertz
1757:watt per square metre per hertz
1305:Radiant energy per unit volume.
457:
2535:Introduction to electrodynamics
837:
2586:
2457:
808:This formula assumes that the
462:
452:
423:perpendicular to the surface:
1:
2450:
2111:Radiant energy received by a
1542:watt per steradian per metre
1501:watt per steradian per hertz
757:of the medium of propagation;
204:is the radiant flux received;
103:
57:. Irradiance is often called
2615:10.1016/0038-092X(60)90062-1
2531:Griffiths, David J. (1999).
46:per square metre (W⋅m). The
7:
2385:
2236:recommend that radiometric
410:
119:quantities), is defined as
83:, depending on whether the
10:
2658:
974:
218:by a surface, we speak of
2348:are denoted with suffix "
2312:are denoted with suffix "
2199:
2156:
2080:
2037:
1961:
1918:
1842:
1771:
1687:
1640:
1562:
1519:
1433:
1396:
1309:
1270:
1227:
1222:
1219:
1216:
1213:
812:is negligible; i.e. that
99:Mathematical definitions
2234:Standards organizations
2096:joule per square metre
988:and diffuse irradiance
832:optical frequency range
810:magnetic susceptibility
802:impedance of free space
507:is the Poynting vector;
2576:Renewable Energy World
2382:
2157:Radiant exposure of a
2038:Radiant exitance of a
1977:watt per square metre
1858:watt per square metre
1707:watt per square metre
1286:joule per cubic metre
1272:Radiant energy density
1131:
908:
728:
485:
394:
304:
180:
2439:Spectral flux density
2380:
2286:for radiant exitance.
1740:Spectral flux density
1132:
909:
828:magnetic permeability
729:
486:
395:
305:
181:
42:of irradiance is the
2444:Stefan–Boltzmann law
2270:for radiant energy,
1016:
853:
543:
501:is the time-average;
430:
334:
244:
126:
38:per unit area. The
2635:Physical quantities
2607:1960SoEn....4....1L
2424:Solar azimuth angle
1736:Spectral irradiance
1610:Specific intensity
1196:
1168:SI radiometry units
1159:SI radiometry units
956:(radiant flux: 1.5
791:vacuum permittivity
780:vacuum permeability
711:
660:
604:
517:to the surface and
407:is the wavelength.
226:Spectral irradiance
73:Spectral irradiance
2568:Quaschning, Volker
2383:
2278:for radiant flux,
1887:Spectral radiosity
1484:Spectral intensity
1165:
1127:
904:
724:
695:
644:
588:
530:linearly polarized
525:For a propagating
481:
390:
317:is the frequency.
300:
195:partial derivative
176:
2475:978-1-108-42216-1
2223:
2222:
2125:Spectral exposure
2006:Spectral exitance
1607:Spectral radiance
1435:Radiant intensity
963:, distance: 4.34
898:
870:
693:
642:
586:
385:
295:
171:
63:radiant intensity
2647:
2619:
2618:
2590:
2584:
2583:
2564:
2555:
2554:
2538:
2528:
2522:
2521:
2519:
2518:
2499:
2488:
2487:
2461:
2429:Solar irradiance
2371:
2364:
2355:
2342:
2323:
2318:" (Greek letter
2306:
2287:
2285:
2282:for irradiance,
2281:
2277:
2273:
2269:
2265:
2260:
2245:
2231:
2176:
2139:
2093:
2082:Radiant exposure
2057:
2020:
1974:
1963:Radiant exitance
1938:
1901:
1855:
1819:
1803:
1799:
1795:
1787:
1783:
1772:Irradiance of a
1754:
1704:
1664:
1623:
1575:
1539:
1498:
1446:
1410:
1369:
1320:
1283:
1240:
1197:
1190:
1183:
1176:
1169:
1164:
1136:
1134:
1133:
1128:
1123:
1122:
1121:
1104:
1091:
1090:
1089:
1072:
1059:
1058:
1057:
1043:
1030:
1029:
1028:
977:Solar irradiance
971:Solar irradiance
954:Alpha Centauri A
943:
939:
929:
924:is the distance;
923:
913:
911:
910:
905:
899:
897:
896:
895:
876:
871:
863:
755:refractive index
733:
731:
730:
725:
710:
705:
704:
694:
692:
691:
690:
674:
659:
654:
653:
643:
638:
637:
632:
631:
618:
603:
598:
597:
587:
585:
584:
579:
578:
562:
557:
556:
555:
532:electromagnetic
500:
490:
488:
487:
482:
465:
460:
455:
444:
443:
442:
399:
397:
396:
391:
386:
384:
376:
375:
374:
373:
359:
354:
353:
346:
327:, is defined as
309:
307:
306:
301:
296:
294:
286:
285:
284:
283:
269:
264:
263:
256:
237:, is defined as
220:radiant exitance
185:
183:
182:
177:
172:
170:
162:
161:
160:
159:
145:
140:
139:
138:
2657:
2656:
2650:
2649:
2648:
2646:
2645:
2644:
2625:
2624:
2623:
2622:
2591:
2587:
2565:
2558:
2551:
2529:
2525:
2516:
2514:
2513:catalogue. 1989
2501:
2500:
2491:
2476:
2462:
2458:
2453:
2448:
2413:Light diffusion
2388:
2375:
2374:
2365:
2358:
2343:
2326:
2307:
2290:
2283:
2279:
2275:
2271:
2267:
2263:
2261:
2248:
2232:
2228:
2219:
2175:
2166:
2138:
2129:
2092:
2086:
2056:
2047:
2019:
2010:
1973:
1967:
1937:
1928:
1919:Radiosity of a
1900:
1891:
1854:
1848:
1818:
1809:
1801:
1797:
1793:
1790:solar flux unit
1785:
1781:
1753:
1744:
1738:
1703:
1697:
1691:
1663:
1654:
1622:
1613:
1609:
1574:
1568:
1538:
1529:
1497:
1488:
1445:
1439:
1413:watt per metre
1409:
1402:
1368:
1361:
1319:
1315:
1282:
1276:
1239:
1233:
1195:
1194:
1167:
1161:
1108:
1100:
1099:
1095:
1076:
1068:
1067:
1063:
1047:
1039:
1038:
1034:
1024:
1023:
1019:
1017:
1014:
1013:
1008:
1001:
994:
987:
979:
973:
961:
941:
937:
927:
921:
891:
887:
880:
875:
862:
854:
851:
850:
840:
825:
818:
799:
788:
777:
746:
706:
700:
699:
686:
682:
678:
673:
655:
649:
648:
633:
627:
623:
619:
617:
599:
593:
592:
580:
574:
570:
566:
561:
551:
550:
546:
544:
541:
540:
498:
461:
456:
451:
438:
437:
433:
431:
428:
427:
421:Poynting vector
413:
377:
369:
368:
364:
360:
358:
342:
341:
337:
335:
332:
331:
326:
287:
279:
278:
274:
270:
268:
252:
251:
247:
245:
242:
241:
236:
228:
203:
163:
155:
154:
150:
146:
144:
134:
133:
129:
127:
124:
123:
114:
106:
101:
17:
12:
11:
5:
2655:
2654:
2643:
2642:
2637:
2621:
2620:
2585:
2556:
2549:
2523:
2489:
2474:
2468:. p. 60.
2455:
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2421:
2415:
2410:
2405:
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2384:
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2356:
2324:
2288:
2246:
2225:
2224:
2221:
2220:
2218:
2217:
2212:
2207:
2201:
2197:
2196:
2183:
2180:
2177:
2170:
2163:
2162:
2155:
2146:
2143:
2140:
2133:
2127:
2121:
2120:
2109:
2100:
2097:
2094:
2090:
2084:
2078:
2077:
2064:
2061:
2058:
2051:
2044:
2043:
2036:
2027:
2024:
2021:
2014:
2008:
2002:
2001:
1990:
1981:
1978:
1975:
1971:
1965:
1959:
1958:
1945:
1942:
1939:
1932:
1925:
1924:
1917:
1908:
1905:
1902:
1895:
1889:
1883:
1882:
1871:
1862:
1859:
1856:
1852:
1846:
1840:
1839:
1826:
1823:
1820:
1813:
1806:
1805:
1798:10 W⋅m⋅Hz
1786:10 W⋅m⋅Hz
1770:
1761:
1758:
1755:
1748:
1742:
1732:
1731:
1720:
1711:
1708:
1705:
1701:
1695:
1685:
1684:
1671:
1668:
1665:
1658:
1651:
1650:
1641:Radiance of a
1639:
1630:
1627:
1624:
1617:
1611:
1603:
1602:
1591:
1582:
1579:
1576:
1572:
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1559:
1546:
1543:
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1533:
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1518:
1505:
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1417:
1414:
1411:
1404:
1399:
1398:
1395:
1382:
1376:
1370:
1363:
1359:
1353:
1352:
1351:in Astronomy.
1345:
1332:
1326:
1321:
1317:
1313:
1307:
1306:
1303:
1290:
1287:
1284:
1280:
1274:
1268:
1267:
1264:
1251:
1246:
1241:
1237:
1231:
1229:Radiant energy
1225:
1224:
1221:
1218:
1215:
1211:
1210:
1207:
1204:
1201:
1193:
1192:
1185:
1178:
1170:
1166:
1160:
1157:
1146:solar exposure
1138:
1137:
1126:
1120:
1117:
1114:
1111:
1107:
1103:
1098:
1094:
1088:
1085:
1082:
1079:
1075:
1071:
1066:
1062:
1056:
1053:
1050:
1046:
1042:
1037:
1033:
1027:
1022:
1006:
999:
992:
985:
975:Main article:
972:
969:
959:
946:
945:
935:
925:
915:
914:
902:
894:
890:
886:
883:
879:
874:
869:
866:
861:
858:
839:
836:
823:
816:
806:
805:
797:
794:
786:
783:
775:
772:
765:speed of light
758:
748:
744:
735:
734:
723:
720:
717:
714:
709:
703:
698:
689:
685:
681:
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663:
658:
652:
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641:
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622:
616:
613:
610:
607:
602:
596:
591:
583:
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573:
569:
565:
560:
554:
549:
523:
522:
508:
502:
492:
491:
480:
477:
474:
471:
468:
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436:
412:
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372:
367:
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324:
311:
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293:
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282:
277:
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259:
255:
250:
234:
227:
224:
212:
211:
205:
201:
198:
187:
186:
175:
169:
166:
158:
153:
149:
143:
137:
132:
112:
105:
102:
100:
97:
15:
9:
6:
4:
3:
2:
2653:
2652:
2641:
2638:
2636:
2633:
2632:
2630:
2616:
2612:
2608:
2604:
2600:
2596:
2589:
2581:
2577:
2573:
2569:
2563:
2561:
2552:
2550:0-13-805326-X
2546:
2542:
2541:Prentice-Hall
2537:
2536:
2527:
2512:
2508:
2507:ISO 9288:1989
2504:
2498:
2496:
2494:
2485:
2481:
2477:
2471:
2467:
2460:
2456:
2445:
2442:
2440:
2437:
2435:
2432:
2430:
2427:
2425:
2422:
2419:
2416:
2414:
2411:
2409:
2406:
2404:
2401:
2399:
2396:
2394:
2391:
2390:
2379:
2369:
2363:
2361:
2353:
2352:
2347:
2341:
2339:
2337:
2335:
2333:
2331:
2329:
2321:
2317:
2316:
2311:
2305:
2303:
2301:
2299:
2297:
2295:
2293:
2259:
2257:
2255:
2253:
2251:
2243:
2239:
2235:
2230:
2226:
2216:
2213:
2211:
2208:
2206:
2203:
2202:
2198:
2195:
2191:
2187:
2184:
2181:
2178:
2174:
2169:
2165:
2164:
2160:
2154:
2150:
2147:
2144:
2141:
2137:
2132:
2128:
2126:
2122:
2118:
2114:
2110:
2108:
2104:
2101:
2098:
2095:
2089:
2085:
2083:
2079:
2076:
2072:
2068:
2065:
2062:
2059:
2055:
2050:
2046:
2045:
2041:
2035:
2031:
2028:
2025:
2022:
2018:
2013:
2009:
2007:
2003:
1999:
1995:
1992:Radiant flux
1991:
1989:
1985:
1982:
1979:
1976:
1970:
1966:
1964:
1960:
1957:
1953:
1949:
1946:
1943:
1940:
1936:
1931:
1927:
1926:
1922:
1916:
1912:
1909:
1906:
1903:
1899:
1894:
1890:
1888:
1884:
1880:
1876:
1873:Radiant flux
1872:
1870:
1866:
1863:
1860:
1857:
1851:
1847:
1845:
1841:
1838:
1834:
1830:
1827:
1824:
1821:
1817:
1812:
1808:
1807:
1791:
1779:
1775:
1769:
1765:
1762:
1759:
1756:
1752:
1747:
1743:
1741:
1737:
1733:
1729:
1725:
1722:Radiant flux
1721:
1719:
1715:
1712:
1709:
1706:
1700:
1696:
1694:
1690:
1686:
1683:
1679:
1675:
1672:
1669:
1666:
1662:
1657:
1653:
1652:
1648:
1644:
1638:
1634:
1631:
1628:
1625:
1621:
1616:
1612:
1608:
1604:
1600:
1596:
1592:
1590:
1586:
1583:
1580:
1577:
1571:
1567:
1565:
1561:
1558:
1554:
1550:
1547:
1544:
1541:
1537:
1532:
1528:
1527:
1523:
1517:
1513:
1509:
1506:
1503:
1500:
1496:
1491:
1487:
1485:
1481:
1477:
1473:
1471:
1467:
1463:
1460:
1458:
1454:
1452:
1448:
1442:
1438:
1436:
1432:
1429:
1425:
1421:
1418:
1415:
1412:
1408:
1401:
1400:
1394:
1390:
1386:
1383:
1381:
1377:
1375:
1371:
1367:
1360:
1358:
1357:Spectral flux
1354:
1350:
1346:
1344:
1340:
1336:
1333:
1330:
1327:
1325:
1322:
1314:
1312:
1308:
1304:
1302:
1298:
1294:
1291:
1288:
1285:
1279:
1275:
1273:
1269:
1265:
1263:
1259:
1255:
1252:
1250:
1247:
1245:
1242:
1236:
1232:
1230:
1226:
1212:
1198:
1191:
1186:
1184:
1179:
1177:
1172:
1171:
1163:
1156:
1153:
1151:
1147:
1143:
1124:
1105:
1096:
1092:
1073:
1064:
1060:
1044:
1035:
1031:
1020:
1012:
1011:
1010:
1005:
998:
991:
984:
978:
968:
966:
962:
955:
949:
936:
933:
926:
920:
919:
918:
900:
892:
888:
884:
881:
877:
872:
867:
864:
859:
856:
849:
848:
847:
845:
835:
833:
829:
822:
815:
811:
803:
795:
792:
784:
781:
773:
770:
766:
762:
759:
756:
752:
749:
743:
740:
739:
738:
721:
718:
715:
712:
707:
696:
687:
683:
679:
675:
670:
667:
664:
661:
656:
645:
639:
628:
624:
620:
614:
611:
608:
605:
600:
589:
575:
571:
567:
563:
558:
547:
539:
538:
537:
535:
531:
528:
520:
516:
512:
509:
506:
503:
497:
496:
495:
478:
475:
472:
469:
445:
434:
426:
425:
424:
422:
418:
408:
406:
387:
381:
365:
355:
350:
347:
338:
330:
329:
328:
323:
318:
316:
297:
291:
275:
265:
260:
257:
248:
240:
239:
238:
233:
223:
221:
217:
209:
206:
199:
196:
192:
191:
190:
173:
167:
141:
130:
122:
121:
120:
118:
111:
96:
94:
90:
86:
82:
78:
74:
70:
68:
64:
60:
56:
52:
49:
45:
41:
37:
33:
30:
26:
22:
2598:
2595:Solar Energy
2594:
2588:
2579:
2575:
2534:
2526:
2515:. Retrieved
2506:
2465:
2459:
2349:
2313:
2229:
2193:
2189:
2185:
2172:
2167:
2158:
2152:
2148:
2135:
2130:
2116:
2112:
2106:
2102:
2087:
2074:
2070:
2066:
2053:
2048:
2039:
2033:
2029:
2016:
2011:
1997:
1993:
1987:
1983:
1968:
1955:
1951:
1947:
1934:
1929:
1920:
1914:
1910:
1897:
1892:
1878:
1874:
1868:
1864:
1849:
1836:
1832:
1828:
1815:
1810:
1773:
1767:
1763:
1750:
1745:
1735:
1727:
1723:
1717:
1713:
1698:
1693:Flux density
1688:
1681:
1677:
1673:
1660:
1655:
1646:
1642:
1636:
1632:
1619:
1614:
1598:
1594:
1588:
1584:
1569:
1556:
1552:
1548:
1535:
1530:
1521:
1515:
1511:
1507:
1494:
1489:
1475:
1469:
1465:
1461:
1440:
1427:
1423:
1419:
1406:
1392:
1388:
1384:
1365:
1342:
1338:
1334:
1311:Radiant flux
1300:
1296:
1292:
1277:
1261:
1257:
1253:
1234:
1162:
1154:
1139:
1003:
996:
989:
982:
980:
950:
947:
932:radiant flux
916:
844:point source
841:
838:Point source
820:
813:
807:
760:
750:
741:
736:
526:
524:
518:
510:
504:
493:
417:radiant flux
414:
404:
402:
321:
319:
314:
312:
231:
229:
215:
213:
210:is the area.
207:
188:
109:
107:
72:
71:
67:radiant flux
66:
35:
31:
29:radiant flux
24:
18:
2582:(5): 90–93.
2403:Illuminance
2244:quantities.
1647:directional
1599:directional
1522:directional
1476:directional
117:photometric
2640:Radiometry
2629:Categories
2517:2015-03-15
2451:References
2434:Solar noon
2408:Insolation
2346:wavelength
2238:quantities
2215:Photometry
2210:Radiometry
2200:See also:
1802:10 Jy
1794:1 sfu
1689:Irradiance
1629:W⋅sr⋅m⋅Hz
1524:quantity.
1478:quantity.
1349:luminosity
1206:Dimension
1150:insolation
819:≈ 1 where
534:plane wave
527:sinusoidal
104:Irradiance
89:dimensions
81:wavelength
25:irradiance
21:radiometry
2484:991641816
2310:frequency
1844:Radiosity
1782:1 Jy
1451:steradian
1449:watt per
1372:watt per
1200:Quantity
885:π
719:α
716:
668:α
665:
625:ε
612:α
609:
572:μ
476:α
473:
467:⟩
449:⟨
382:λ
379:∂
362:∂
351:λ
292:ν
289:∂
272:∂
261:ν
193:∂ is the
165:∂
152:Φ
148:∂
77:frequency
59:intensity
55:astronomy
2601:(3): 1.
2570:(2003).
2418:PI curve
2386:See also
1724:received
1564:Radiance
1504:W⋅sr⋅Hz
1142:integral
411:Property
85:spectrum
48:CGS unit
32:received
2603:Bibcode
2398:Fluence
2159:surface
2145:J⋅m⋅Hz
2117:surface
2113:surface
2040:surface
2026:W⋅m⋅Hz
1998:surface
1994:emitted
1921:surface
1907:W⋅m⋅Hz
1879:surface
1875:leaving
1774:surface
1760:W⋅m⋅Hz
1728:surface
1670:W⋅sr⋅m
1643:surface
1595:surface
1581:W⋅sr⋅m
1545:W⋅sr⋅m
1223:Symbol
1217:Symbol
930:is the
826:is the
800:is the
789:is the
778:is the
763:is the
753:is the
216:emitted
197:symbol;
40:SI unit
36:surface
27:is the
2547:
2482:
2472:
2393:Albedo
2242:photon
1788:) and
1778:jansky
1331:= J/s
1209:Notes
1148:" or "
1000:e,refl
993:e,diff
917:where
769:vacuum
737:where
515:normal
494:where
403:where
313:where
189:where
1996:by a
1726:by a
1374:hertz
1244:joule
1220:Name
1214:Name
1203:Unit
986:e,dir
499:⟨ • ⟩
93:hertz
34:by a
2545:ISBN
2480:OCLC
2470:ISBN
2182:J/m
2099:J/m
2063:W/m
1980:W/m
1944:W/m
1861:W/m
1825:W/m
1710:W/m
1659:e,Ω,
1618:e,Ω,
1534:e,Ω,
1493:e,Ω,
1416:W/m
1324:watt
1289:J/m
1140:The
44:watt
2611:doi
2511:ISO
2274:or
2266:or
1804:).
1573:e,Ω
1444:e,Ω
1152:".
767:in
713:cos
662:cos
606:cos
470:cos
325:e,λ
235:e,ν
79:or
51:erg
19:In
2631::
2609:.
2597:.
2578:.
2574:.
2559:^
2543:.
2509:.
2505:.
2492:^
2478:.
2370:".
2359:^
2354:".
2327:^
2320:nu
2291:^
2249:^
2205:SI
2171:e,
2134:e,
2052:e,
2015:e,
1933:e,
1896:e,
1814:e,
1800:=
1796:=
1784:=
1749:e,
1457:sr
1455:W/
1405:e,
1380:Hz
1378:W/
1364:e,
965:ly
842:A
834:.
222:.
69:.
23:,
2617:.
2613::
2605::
2599:4
2580:6
2553:.
2520:.
2486:.
2368:Ω
2351:λ
2315:ν
2284:W
2280:I
2276:F
2272:P
2268:E
2264:W
2194:T
2192:⋅
2190:L
2188:⋅
2186:M
2173:λ
2168:H
2153:T
2151:⋅
2149:M
2136:ν
2131:H
2107:T
2105:⋅
2103:M
2091:e
2088:H
2075:T
2073:⋅
2071:L
2069:⋅
2067:M
2054:λ
2049:M
2034:T
2032:⋅
2030:M
2017:ν
2012:M
1988:T
1986:⋅
1984:M
1972:e
1969:M
1956:T
1954:⋅
1952:L
1950:⋅
1948:M
1935:λ
1930:J
1915:T
1913:⋅
1911:M
1898:ν
1893:J
1869:T
1867:⋅
1865:M
1853:e
1850:J
1837:T
1835:⋅
1833:L
1831:⋅
1829:M
1816:λ
1811:E
1792:(
1780:(
1768:T
1766:⋅
1764:M
1751:ν
1746:E
1718:T
1716:⋅
1714:M
1702:e
1699:E
1682:T
1680:⋅
1678:L
1676:⋅
1674:M
1661:λ
1656:L
1637:T
1635:⋅
1633:M
1620:ν
1615:L
1589:T
1587:⋅
1585:M
1570:L
1557:T
1555:⋅
1553:L
1551:⋅
1549:M
1536:λ
1531:I
1516:T
1514:⋅
1512:L
1510:⋅
1508:M
1495:ν
1490:I
1470:T
1468:⋅
1466:L
1464:⋅
1462:M
1441:I
1428:T
1426:⋅
1424:L
1422:⋅
1420:M
1407:λ
1403:Φ
1393:T
1391:⋅
1389:L
1387:⋅
1385:M
1366:ν
1362:Φ
1343:T
1341:⋅
1339:L
1337:⋅
1335:M
1329:W
1318:e
1316:Φ
1301:T
1299:⋅
1297:L
1295:⋅
1293:M
1281:e
1278:w
1262:T
1260:⋅
1258:L
1256:⋅
1254:M
1249:J
1238:e
1235:Q
1189:e
1182:t
1175:v
1125:.
1119:l
1116:f
1113:e
1110:r
1106:,
1102:e
1097:E
1093:+
1087:f
1084:f
1081:i
1078:d
1074:,
1070:e
1065:E
1061:+
1055:r
1052:i
1049:d
1045:,
1041:e
1036:E
1032:=
1026:e
1021:E
1007:e
1004:E
997:E
990:E
983:E
960:☉
958:L
944:.
942:r
938:A
934:;
928:P
922:r
901:.
893:2
889:r
882:4
878:P
873:=
868:A
865:P
860:=
857:E
824:r
821:μ
817:r
814:μ
804:.
798:0
796:Z
793:;
787:0
785:ε
782:;
776:0
774:μ
771:;
761:c
751:n
745:m
742:E
722:,
708:2
702:m
697:E
688:0
684:Z
680:2
676:n
671:=
657:2
651:m
646:E
640:2
635:c
629:0
621:n
615:=
601:2
595:m
590:E
582:c
576:0
568:2
564:n
559:=
553:e
548:E
521:.
519:S
511:α
505:S
479:,
463:|
458:S
453:|
446:=
440:e
435:E
405:λ
388:,
371:e
366:E
356:=
348:,
344:e
339:E
322:E
315:ν
298:,
281:e
276:E
266:=
258:,
254:e
249:E
232:E
208:A
202:e
200:Φ
174:,
168:A
157:e
142:=
136:e
131:E
113:e
110:E
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