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I have spectral radiance data in SRUs (spectral radiance units), as a function of wavelength: $$a = \mu W cm^{-2} sr^{-1} nm^{-1} $$

However, I am working with software which requires my data in the form: $$b=mWcm^{-2}sr^{-1}\mu m^{-1}$$

Are these two units are equivalent?

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closed as too localized by Emilio Pisanty, Waffle's Crazy Peanut, Sklivvz, Manishearth Jan 15 '13 at 6:30

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up vote 2 down vote accepted

Well, $1\textrm{ mW}=1000\, \mu \textrm{W} $ and $1\,\mu\textrm{m}=1000\textrm{ nm}$, so that $$ 1\textrm{ mW}\,\textrm{cm}^{-2}\textrm{sr}^{-1}\mu\textrm{m}^{-1}= 1000\textrm{ mW}\,\textrm{cm}^{-2}\textrm{sr}^{-1}\left(1000\textrm{ nm}\right)^{-1}= 1 \,\mu\textrm{W}\,\textrm{cm}^{-2}\textrm{sr}^{-1}\textrm{nm}^{-1} $$ and both units are exactly equivalent.

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Thank you. I had my head lost in all the SI units! –  MartinB Jan 14 '13 at 16:40
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