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Area Lighting / Radiation, quantities and units

IEV ref845-01-33

Symbol
G

en
geometric extent (of a beam of rays)
integral taken over the whole beam of the elementary quantity dG defined by the equivalent formulae

dG= dAcosθd A cos θ l 2 =dAcosθdΩ MathType@MTEF@5@5@+=feaagCart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHXgaruavP1wzZbItLDhis9wBH5garmWu51MyVXgarqqtubsr4rNCHbGeaGqipG0dh9qqWrVepG0dbbL8F4rqqrVepeea0xe9LqFf0xc9q8qqaqFn0lXdHiVcFbIOFHK8Feea0dXdar=Jb9hs0dXdHuk9fr=xfr=xfrpeWZqaaeaaciWacmGadaGadeaabaGaaqaaaOqaaiaabsgacaWGhbGaeyypa0ZaaSaaaeaacaqGKbGaamyqaiabgwSixlGacogacaGGVbGaai4CaiabeI7aXjabgwSixlaabsgaceWGbbGbauaacqGHflY1ciGGJbGaai4BaiaacohacuaH4oqCgaqbaaqaaiaadYgadaahaaWcbeqaaiaaikdaaaaaaOGaeyypa0JaaeizaiaadgeacqGHflY1ciGGJbGaai4BaiaacohacqaH4oqCcqGHflY1caqGKbGaeuyQdCfaaa@5BA2@

where dA and dA′ are the areas of two sections of an element of the beam separated by the distance l; θ and θ′ are the angles between the direction of that elementary beam and the normals to dA and dA′; dΩ= d A cos θ l 2 MathType@MTEF@5@5@+=feaagCart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHXgaruavP1wzZbItLDhis9wBH5garmWu51MyVXgarqqtubsr4rNCHbGeaGqipG0dh9qqWrVepG0dbbL8F4rqqrVepeea0xe9LqFf0xc9q8qqaqFn0lXdHiVcFbIOFHK8Feea0dXdar=Jb9hs0dXdHuk9fr=xfr=xfrpeWZqaaeaaciWacmGadaGadeaabaGaaqaaaOqaaiaabsgacqqHPoWvcqGH9aqpdaWcaaqaaiaabsgaceWGbbGbauaacqGHflY1ciGGJbGaai4BaiaacohacuaH4oqCgaqbaaqaaiaadYgadaahaaWcbeqaaiaaikdaaaaaaaaa@434B@ is the solid angle subtended by dA′ from a point on dA.

unit : m2 • sr

Note – For a beam propagating through successive non-diffusing media, the quantity G · n2, where n is the refractive index, is invariant. That quantity is called the optical extent.


fr
étendue géométrique (d'un faisceau de rayons) f
intégrale étendue à tout le faisceau de la grandeur élémentaire dG définie par les formules équivalentes

dG= dAcosθd A cos θ l 2 =dAcosθdΩ MathType@MTEF@5@5@+=feaagCart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHXgaruavP1wzZbItLDhis9wBH5garmWu51MyVXgarqqtubsr4rNCHbGeaGqipG0dh9qqWrVepG0dbbL8F4rqqrVepeea0xe9LqFf0xc9q8qqaqFn0lXdHiVcFbIOFHK8Feea0dXdar=Jb9hs0dXdHuk9fr=xfr=xfrpeWZqaaeaaciWacmGadaGadeaabaGaaqaaaOqaaiaabsgacaWGhbGaeyypa0ZaaSaaaeaacaqGKbGaamyqaiabgwSixlGacogacaGGVbGaai4CaiabeI7aXjabgwSixlaabsgaceWGbbGbauaacqGHflY1ciGGJbGaai4BaiaacohacuaH4oqCgaqbaaqaaiaadYgadaahaaWcbeqaaiaaikdaaaaaaOGaeyypa0JaaeizaiaadgeacqGHflY1ciGGJbGaai4BaiaacohacqaH4oqCcqGHflY1caqGKbGaeuyQdCfaaa@5BA2@

où dA et dA′ sont les aires de deux sections d'un élément du faisceau séparées par la distance l; θ et θ′ sont les angles entre la direction de ce faisceau élémentaire et les normales à dA et dA′; dΩ= d A cos θ l 2 MathType@MTEF@5@5@+=feaagCart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHXgaruavP1wzZbItLDhis9wBH5garmWu51MyVXgarqqtubsr4rNCHbGeaGqipG0dh9qqWrVepG0dbbL8F4rqqrVepeea0xe9LqFf0xc9q8qqaqFn0lXdHiVcFbIOFHK8Feea0dXdar=Jb9hs0dXdHuk9fr=xfr=xfrpeWZqaaeaaciWacmGadaGadeaabaGaaqaaaOqaaiaabsgacqqHPoWvcqGH9aqpdaWcaaqaaiaabsgaceWGbbGbauaacqGHflY1ciGGJbGaai4BaiaacohacuaH4oqCgaqbaaqaaiaadYgadaahaaWcbeqaaiaaikdaaaaaaaaa@434B@ est l'angle solide sous-tendu par dA′ à partir d'un point de dA.

unité : m2 • sr

Note – Pour un faisceau se propageant dans des milieux non diffusants successifs, la grandeur G · n2, où n est l'indice de réfraction, est un invariant. Cette grandeur est appelée l'étendue optique.


ar
مدى هندسي لحزمة أشعة

de
geometrischer Leitwert, m
geometrischer Fluss (eines Strahlenbündels), m

es
flujo geométrico

fi
geometrinen vuo

it
estensione geometrica

ko
전공속, 빔광선

ja
全光束
光ビームの幾何学的広がり
幾何学的広がり

no
nb geometrisk omfang

nn geometrisk omfang

pl
wskaźnik geometryczny (wiązki promieniowania)

pt
extensão geométrica (de um feixe de raios)

sr
геометријско ширење , <снопа зракова> с јд

sv
geometrisk omfattning

Publication date: 1987
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