What solid angle does that angular pixel represent?
 GM)\)\kNF    r;&]?9)W0  To answer that question we project out from the local axis of the detector to construct a sphere some long distance away from the detector, centered on the detector. 
We then (conceptually) fire rays from this point at x, y angles of (5, 40), (5, 41), (6, 41), and (6, 40). Now we know that patch of area, we can compute the solid angle subtended by that angular pixel.
 _hAj2%SL  How is Radiant Intensity Defined   M/::`yJQu    fhBO~o+K>    yt/20a  红色标出的那句是什么意思?
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