The inhomogeneity of the atmosphere causes curvature (refraction) of the beam path of ultra-short radio waves. Under normal conditions, this trajectory curves towards the surface of the Earth, and its curvature is about one quarter of the curvature of the earth's surface. Under critical conditions, the appearance of the phenomenon of "superrefraction" is possible. A feature of ultra-short radio waves is the fact that meteorological conditions influence their propagation. Measurements of meteorological parameters at h1 = 2 and h2 = 10 meters were carried out using an atmospheric-soil measuring complex installed in the southwestern part of the Vitim Plateau. It has been established that in this layer the spread of refractivity gradient values is from –0.820 to +0.307 N-units. It was found that meteorological conditions favorable for the appearance of superrefraction are observed in the given area in the summer.
An experimental wind wave monitoring station has been set up on the eastern coast of Middle Baikal. Tests were carried out by direct measurements using a video recorder installed on a measuring pole near the coastline. The characteristics of the wind were measured synchronously with an anemometer. In the conditions of open Baikal in shallow water in the daytime, the dependence of the height of the waves on the speed and direction of the wind has been established. In the morning, with an increase in the wind speed of the southwestern direction, the generation of wind waves begins. The maximum height of the waves in the second half of the day with the western wind direction is established. The measurements were taken in autumn.
The meteorological situation, which depend on the climatic features of the geographical region, have a significant impact on the propagation of ultrashort radio waves. This work presents the results of a study of the variability of the refractive properties of the surface atmospheric layer in the city of Ulan-Ude influence on the level of the UHF signal in July and October 2021. According to the data from the meteorological station of the city of Ulan-Ude, we calculated the atmospheric refraction. The measurement of the received signal level has been with a Rohde &Schwarz portable TV signal analyzer. We found a high correlation between the averaged signals with refraction.
The result of measurement of the cross-polarized component of the reflected field from liquids with different permittivity are presented. The cross-polarized component of the field is observed for liquid dielectrics with a large value of the imaginary part of the complex permittivity. The mechanism of excitation of this component is proposed.
Seasonal variability of the vertical structure of the atmosphere leads to "slow" fading of the VHF signal level at the receiving point. They are attributed to smooth changes in the layered factors that determine the average refractivity gradient of the atmosphere. Statistical characteristics of temporal changes in the refractive properties of the atmosphere are necessary, for example, for a quantitative assessment of the fluctuation and energy characteristics of a signal during long-range tropospheric propagation of VHF. The paper presents the dynamics of the vertical temperature gradient and the calculation of the vertical gradients of humidity, refraction, as well as the dry and wet components of the refraction of the surface atmosphere according to the data of the aerological station Ust-Barguzin.
The dynamics of the atmosphere has a significant impact on the propagation of ultrashort radio waves. The atmospheric refraction index is the main radio meteorological characteristic of ultrashort waves. Calculations and construction of contours of the refractive index N in the atmosphere of the Republic of Buryatia and the Irkutsk region were carried out. The contours of average N for the study area for January and July 2020 are presented.
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