[Radiance-general] Calculation of solar declination in sun.c

[Martin Gut]

Dear Radiance Experts,

I have two questions regarding the calculation of solar declination:


1.       Why has the year in function sdec  in  file sun.c  368 days instead of 365 as in the original formula from Cooper ?

return( 0.4093 * sin( (2*PI/368) * (jd - 81) ) )

https://github.com/NREL/Radiance/blob/master/src/gen/sun.c


2.       Why does Radiance not use a better formula, which takes into account, that the Earth orbit is not a circle?

With today computing power, there is no more reason to use this simple formula

Thanks in advance


Martin



Dipl.-Ing. (FH) Martin Gut
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