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General formula for refractive index of moist air?

  1. Jun 10, 2012 #1
    Not sure if one exists but can anyone point me in the right direction?

    Looking for a formula which includes the temperature and partial/total pressure dependencies? I'm trying to find the trajectory of a photon through a cloud of varying (but known) temperature, pressure and humidity.

    If there is no formula are there tables?

    My search has so far found very little. Looking at infra-red/visible frequencies.

  2. jcsd
  3. Jun 10, 2012 #2
    Wolfram Alpha provides the values for moist air so there is some formula I suppose.
    Just Google "index refraction moist air".
    However, I am afraid you may be looking for data that is not relevant for your problem.
    A cloud is not moist air but air with small droplets of water in suspension. The photon will suffer scattering on the dropplets and this may be the main mechanism to determine the trajectory.
    If you are really interested in moist air, the changes of index with humidity are quite negligible.
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