[Radiance-general] actual radiance value

[Jia Hu]

Sorry to interrupt you, I can access the paper now. Thanks.


On Sat, Jul 16, 2011 at 12:16 AM, Jia Hu <hujia06 at gmail.com> wrote:

> Hello experts:
>
> Is the following understanding of "radiance" in the Radiance program
> correct?
>
> If I input irradiance (W/m2) values in Gendaylit, the inputted irrdadiance
> values will be converted to zenith luminance (cd/m2) according to Perez's
> model (1990), then luminance will be converted to "radiance" (W/m2*sr) value
> in the visible range by dividing 179 (I did not see "179" in the
> gendaylit.c).
>
> So, the irradiance value calculated by the Radiance program should be
> different from irradiance value in weather file even though the actual
> irradiance values in the weather file are used as an input of
> gendaylit (assuming Perez's model is perfect). But the illuminance /
> luminance values calculated by Radiance should be accurate in theory (also
> assuming Perez's model is accurate).
>
> PS, my school library does not have permission to access the full text of
> the Perez's paper (1993) referred to by Gendaylit program (url:
> http://www.sciencedirect.com/science/article/pii/0038092X9390017I).  If
> allowable, could someone send me this paper?
>
> Thank you,
>
> Jia
>
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