Calculate transmission / reflectivity instead of absolute quantities.
For irradiances / actinic fluxes the transmission T is defined as
 |
(0.1) |
where
is the irradiance / actinic flux,
is the extraterrestrial flux,
and
is the solar zenith angle.
The reflectivity R is defined as
 |
(0.2) |
where
is the radiance,
is the extraterrestrial flux,
and
is the solar zenith angle.
Obviously, reflectivities do not depend on Sun-Earth distance. Please
note the difference to transmittance.
Arve Kylling
2010-03-10