Research on propagation of decimetric radiowaves at high latitudes

In order to study Polar summers during anomalously high signal values affecting radio propagation, research was conducted on decimetric waves over a sea path of 433 km, using antennas with gains of 44 and 46.2 dB, and over a 357 km tundra and woodland path using 46.2 dB gain antennas. In order to evaluate the signals an attenuation factor was used consisting of a ratio of the observed signal to free space reference signals which shows possible antenna losses. Fluctuations and levels are plotted for the indicator. Comparison with meteorological data showed that anomalously high levels are caused by nonuniformities in the refractive index of the lower troposphere which acts as a waveguide when temperature inversions caused by continent sea air movements occur. Amplitude fluctuations are caused by waveguide changes and interference phenomena. The results of the method utilizing attenuation factor statistics are considered better than those of the International Radio Consultive Committee (CCIR).