Determination of radio refractivity using meteorological data

Seasonal and daily variations of radio refractivity have been analyzed in the localities of Lithuania. The method proposed in the Recommendation of International Telecommunication Union (ITU) has been used. The local meteorological data have been used in calculation of radio refractivity. The values of radio refractivity have been determined in Vilnius, Kaunas, Klaipėda, and Mažeikiai. The meteorological data collected in February, April, July and October have been used. The highest values of the radio refractivity have been observed in Klaipėda in the year 2009. In July 2009, the values of the radio refractivity were highest in all localities investigated here and over all the time of the day.