A.Parvaresh - Physics Department, Isfahan University, Iran
S.Nahavadyan - Physics Department, Isfahan University, Iran

Failure to consider anomalous propagation of microwave radiation in the troposphere may result in erroneous meteorological of the atmospheric parameters radio wave propagation and radar measurements. The most commonly occurring anomalous propagation phenomenon over the marine environment is the evaporation duct. The weight of this duct is dependent on meteorological conditions and atmospheric variables and is a major input to microwave propagation. Investigations and predictions of the evaporations duct are important for broadcasting and radar detection. We propose to use the coastal meteorological data to calculate the refractivity in terms of atmospheric pressure water vapor pressure and air temperature.