BeginPackage["Wikicode`Sunlight`"]
SpectralIrradiance::usage = "SpectralIrradiance[wavelength] gives the gives the spectral \
irradiance of sunlight at the top of the atmosphere for a specific wavelength."
Irradiance::usage = "Irradiance[waveMin,waveMax] gives the irradiance of sunlight at the \
top of the atmosphere from the specified range of wavelengths. \"UVB\", \"UVA\", \
\"Visible\", and \"Infrared\" are shortcuts for common wavelength ranges."
Begin["`Private`"]
spectralIrradianceData =
Interpolation[
Import["http://rredc.nrel.gov/solar/spectra/am1.5/ASTMG173/\
ASTMG173.xls"][[2, 3 ;;, ;; 2]], InterpolationOrder -> 1];
SpectralIrradiance[wavelength_] := spectralIrradianceData[wavelength]
Irradiance[waveMin_, waveMax_] :=
Integrate[spectralIrradianceData[x], {x, waveMin, waveMax}]
Irradiance["UVB"] := Irradiance[280, 315]
Irradiance["UVA"] := Irradiance[315, 400]
Irradiance["Visible"] := Irradiance[380, 720]
Irradiance["Infrared"] := Irradiance[700, 4000]
End[]
EndPackage[]
