aerosols

 

 

albedo

1

altitude

meter

altitude angle

degree

anisotropic

 

 

azimuth

degree

backscattering

 

 

candela

lm/sr

candela per square meter

lm/(sr.m2)

clearness index

1

clear sky index

1

clock time

hour

cloud cover, fractional

1

cloud index

1

daylight

 

 

daylight factor

1

directional daylight factor

1

diffuse fraction

1

diffuse horizontal illuminance

lx

diffuse horizontal irradiance

W/m2

diffuse reflectance

1

diffuse solar (sky) radiation

 

 

diffuse transmittance

1

direct horizontal illuminance

lx

direct normal illuminance

lx

direct horizontal irradiance

W/m2

direct normal irradiance

W/m2

direct solar radiation

 

 

elevation angle

degree

equation of time

minute

extraterrestrial normal irradiance

W/m2

extraterrestrial solar radiation

 

 

geographic information system

 

 

geostationary satellite

 

 

global horizontal irradiance

W/m2

global solar radiation

 

 

Greenwich

 

 

ground albedo

1

illuminance

lx

irradiance

W/m2

iso-illuminance curve; isolux curve or line

 

 

isotropic

 

 

latitude

degree

longitude

degree

lumen

 

luminance

cd/m2

luminous efficacy of radiation

lm/W

luminous flux

lm

lux

lm/m2

mean bias deviation

%

meridian

 

 

normal transmittance

1

optical thickness of the atmosphere

1

photometric observer CIE standard

 

 

photopic vision

 

 

pixel

 

 

radiance

W/(m2.sr)

radiant flux

W

Rayleigh atmosphere

 

 

reflectance

1

relative optical air mass

1

root mean square deviation

%

sky, CIE standard clear

 

 

sky, CIE standard overcast

 

 

sky, cloudy

 

 

sky, intermediate

 

 

sky, sunny

 

 

skylight

 

 

slope

degree

solar azimuth

degree

solar constant

1367 W/m2

solar declination

degree

solar elevation

degree

solar hour angle

degree

solar hour angle at sunrise and sunset

degree

solar radiation

 

 

solar zenith angle

degree

solid angle

steradian

spectral luminous efficiency

1

steradian

 

sun-earth distance correction factor

1

sunlight

 

 

sunshine duration

hour

sunshine duration, astronomical

hour

sunshine duration, possible

hour

sunshine duration, relative

1

total turbidity factor

1

transmittance

1

true solar time

hour

variability index

1

visible radiation

 

 

work plane

 

 

zenith angle

degree