  First, we make a revision of the up-to-date Passive Scalar Fields properties:
also, the refractive index is among them. Afterwards, we formulated the
properties that make the family of `isotropic' fractional Brownian motion (with
parameter H) a good candidate to simulate the turbulent refractive index.
Moreover, we obtained its fractal dimension which matches the estimated by
Constantin for passive scalar, and thus the parameter H determines the state of
the turbulence.
  Next, using a path integral velocity representation, with the Markovian
model, to calculate the effects of the turbulence over a system of grids.
  Finally, with the tools of Stochastic Calculus for fractional Brownian
motions we studied the ray-equation coming from the Geometric Optics in the
turbulent case. Our analysis covers those cases where average temperature
gradients are relevant.
