Atmospheric Effects on Communication and Electronic Warfare Systems Within Turkey and Surrounding Areas

This thesis presents the most complete climatology of radio wave (VHF and higher frequencies) tropospheric ducting within Turkey and the surrounding areas ever published. This ducting can result in greatly extended propagation ranges. Atmospheric data from radiosonde upper air observations were collected for a five-year period at stations in Adana, Ankara, Diyarbakir, Isparta, Istanbul, Izmir, Athens, Bucharest, Crete Island, and Tuapse. The upper level and surface ducting yearly average frequencies for these stations were 59.46%, 34.22%, 37.53%, 38.15%, 50.67%, 45.69%, 64.69%, 30.24%, 65.59%, and 21.05%, respectively. Ducts occurred mostly in summer. These frequencies were much higher than previously published climatologies. However, many of these ducts were too shallow to be operationally significant. Atmospheric pressure was correlated with duct heights for some stations, but sometimes the correlation was positive while other times it was negative. In most cases, no correlation was found between duct height and wind speed or direction. Ducts tended to be more common in coastal regions. Regions away from the coast usually have topography limits the effects of the ducts away from the coast, and these inland regions tended to have less ducting occurrence Therefore, these results are most applicable to the coastal regions.