Radio reflectivity of tropospheric layers

Radio reflection coefficients for tropospheric elevated layers are examined as functions of the ratio of layer thickness to the effective radio wavelength and the refractive index structure of the layers. The layer reflectivity is shown to be nearly independent of the refractive index structure for small values of the thickness-wavelength ratio. Results for some layers observed with refractometers show that the reflectivities for large thickness-wavelength ratios are generally larger than those given by the simple linear or constant-gradient layer model.