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Analysis Of VHF Propagation Mechanisms That Cause Interference From The Middle East Within The Southern Coastal Regions Of Cyprus
[Full Text]
AUTHOR(S)
Antonis Constantinides, Panayiotis Michael
KEYWORDS
Abnormal Interference, Propagation Mechanism, Tropospheric Ducting, Refraction.
ABSTRACT
Interference is a very important factor in the planning of digital and analog VHF terrestrial radio services. The most common cause of interference in band II & III occurs under line of sight conditions and thus many times can be skipped. Nevertheless, a more complicated case of interference occurs when an unwanted signal travels beyond the horizon due to atmospheric refraction based on specific weather conditions. A case of such abnormal propagation mechanism has been examined in the Mediterranean Sea during the months June, July and August 2015 due to the radio interference which plaguing the southern coast of Cyprus for years. The model based on which calculations were made is the Weather Research Forecasting (WRF-ARW version 3.4). Furthermore, this study utilizes real world measurements in Band II based on current overseas radio transmissions monitored beyond the horizon in clear spectrum during the hot dry months of the summer. The focus was specifically on the field strength variations versus the type of duct favoring the radio waves in Band II, allowing them to travel between the Middle East to beyond the horizon in Cyprus, since line of sight conditions do not exist between the two regions.
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