Аналітично-емпіричний метод оцінювання ослаблення сигналів супутникових радіонавігаційних систем

Formulation of the problem in general. The article deals with the methodological apparatus for determining the level of radio signal attenuation during electromagnetic wave propagation in the interference conditions created by satellite radio navigation system signal receivers. The purpose of the article is to develop an analytical and empirical method for assessing the attenuation of satellite radio navigation system signals in order to predict the expected interference environment and improve the accuracy of determining the energy parameters of radio interference. Research methods. In the course of writing this article, systematic analysis of electromagnetic wave propagation processes and synthesis of an analytical and empirical method for assessing the signal attenuation of satellite radio navigation systems were applied. This methodological approach has made it possible to obtain expressions for determining the absorption coefficient, considering the obtained radio interference attenuation factor. Literature review. There are known methods and models based on analytical approximation of practical measurement results used to determine the boundaries of the guaranteed reception area or to assess continuous radio interference. However, they are developed for a specific terrain type and are valid only for certain radio bands. Different sources provide either an analysis of existing and prospective means of radio interference to the receivers of satellite radio navigation system signals or an analysis of the technical characteristics of navigation receivers and the limit values of interference levels at which the operability of these receivers will be maintained. However, these data are only partial inputs for assessing the interference situation. Research results. The article analyses several features that should be considered when predicting the interference situation created by the receivers of satellite radio navigation systems. Ways to evaluate the signal attenuation during the propagation of electromagnetic waves on the routes «navigation satellite – radio receiver» and “radio interference transmitter – radio receiver” are proposed. The peculiarities of determining the attenuation of radio interference created by ground-based electronic warfare equipment and equipment deployed on airborne platforms are presented. An analytical and empirical method for estimating the signal attenuation of satellite radio navigation systems is mathematically formalised by combining the classical expressions of the theory of electrodynamics and electromagnetic wave propagation, which characterise the energy parameters of radio signals and empirical expressions for determining the absorption coefficient, taking into account the obtained radio interference attenuation factor. It is shown that using the proposed expressions does not require a significant amount of input data and makes it possible to improve the accuracy of calculations of the energy parameters of radio interference to signal receivers. Research novelty. An aspect of scientific novelty is that the proposed method can be used to consider the attenuation of radio signals during the propagation of electromagnetic waves on the routes «navigation satellite – radio receive» and «radio interference transmitter – radio receiver». Theoretical and practical significance. The combination of classical expressions from the theory of electrodynamics and electromagnetic wave propagation that characterise the energy parameters of signals and the expression for determining the absorption coefficient, taking into account the obtained radio interference attenuation factor, makes it possible to mathematically formalise the proposed analytical and empirical method for estimating the signal attenuation of satellite radio navigation systems. This method can improve the accuracy of determining the energy parameters of radio interference to the receivers of satellite radio navigation systems. Conclusion and future work. The analysis of several features that need to be comprehensively considered when assessing the interference situation created by satellite radio navigation system signal receivers has made it possible to propose ways to evaluate the attenuation of radio signals. Using the proposed analytical and empirical method for assessing the signal attenuation of satellite radio navigation systems does not require a significant amount of initial data. It makes it possible to increase the accuracy of determining the energy parameters of radio interference to signal receivers. Further research can be aimed at solving the problem of expanding the interference resistance of radio electronic systems and the means intended to solve navigation problems.