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Flux per unit projected area per unit solid angle,

  1. Sep 5, 2008 #1
    "flux per unit projected area per unit solid angle,"

    [tex] L = \frac{\partial \Phi}{\partial \left(cos \Theta \right) \ \partial \Omega} [/tex]

    What is this quantity? I mean, I know it's "flux per unit projected area per unit solid angle," how does the math work?

    I know it's not

    [tex]\frac{\partial \Phi}{\partial (Acos \Theta)} \frac{\partial \Phi}{\partial \Omega} [/tex]
     
  2. jcsd
  3. Sep 5, 2008 #2
    Re: Radiance

    well it's either a typo, or some weird convention where people don't follow the rules. I found a few pages later, a table, where the same quantity was given by

    [tex]
    L = \frac{ \partial^{2} \Phi}{\partial(Acos \Theta) \ \partial \Omega}
    [/tex]

    Which of course, makes a heck of a lot more sense.

    It's on page 6 of William Wolfe's intro to Radiometry :-/
     
  4. Sep 5, 2008 #3

    Andy Resnick

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    Re: Radiance

    I think page 6 is a typo- it should be what you have written on post #2. Try emailing William, pointing out the typo- see what he says.
     
  5. Sep 5, 2008 #4
    Re: Radiance

    Email sent. I can't believe I just did that..
     
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