MODELING OF THE INFLUENCE OF ENVIRONMENTAL FACTORSON THE CHARACTERISTICS OF WEAK SIGNAL TRANSMISSION CHANNELS

Abstract

The work addresses the urgent scientific and technical challenge of ensuring the integrity and reliability of weak telemetry signal transmission in communication lines operating under extreme environmental conditions. Modern multidimensional mathematical models consider the simultaneous influence of radiation, temperature, and pressure on the values of signal-to-noise ratio (SNR) and wave resistance as independent factors, but do not take into account the mutual influence of radiation degradation, temperature noise, and baric changes on the quality of transmission of weak signals. For low-amplitude signals, even a slight increase in the noise range resulting from a change in temperature or in linear capacity caused by pressure can become a decisive factor in the complete loss of information. The purpose of the article is to develop an improved mathematical model for quantitative prediction of the signal-to-noise ratio (SNR) and to determine the limits of stable operation of real-time monitoring systems. The proposed model is based on telegraph equations for a line with distributed parameters and comprehensively takes into account the physical mechanisms of radiation ionization of the dielectric (through a change in the linear conductivity of the leakage), the temperature change in the specific active resistance of copper conductors, and the baric deformation of the insulation. The dynamics of the complex attenuation coefficient and the intensity of Nyquist thermal fluctuation noise as well as baric sensitivity of wave resistance were calculated in MATLAB. The simulation results proved the range of uninterrupted information transmission to reduce by 2.5 times under emergency conditions (150°C, 25MPa). The data obtained made it possible to scientifically substantiate the advantages of using heat-resistant fluoroplastic insulation over polyethylene in areas with extreme pressure, since it provides a 12–15 dB higher level of SNR. The scientific novelty of the work lies in the integration of the functions of baric and radiation dependence of linear parameters into a single signal integrity model.