How do I find the reflectivity of a combination of ice on top of water(infinite half-space) as a function of the thickness of ice? I know how to find it for each material, it's just rho = ((root(dielectric constant)-1)/(root(dielectric constant)+1) )^2. I'm given dielectric constants for both. I'm pretty sure we have to calculate the emissivity of the top layer of ice, the emissivity of the underlying water, combine them together somehow, and reflectivity = 1 - emissivity. There is no attenuation, and the thickness varies from 0 to the wavelength. So it's related to the phase shift somehow. But I don't know how to calculate how much power goes from the sun, let's say, through the ice to the water and how it's related to the thickness of the ice. Does anyone know where I can find such an equation?