Pitertsev O. Information technology identifying potential aircraft icing zones

The basis of the results presented in the work are the first time developed method for estimating of informative polarimetric parameters of potential icing zones, an improved method of detection and classification of hazardous meteorological objects with the help of onboard information meteorological systems, in which algorithmic consistency of implementations was added to identify potentially hazardous areas of possible icing and the method of multi-criterion estimation of the risk of icing of airplanes. The determination of zones containing drops of super-cooled liquid that pose a threat of icing in the area of space in the flight direction of an aircraft is proposed to done by analysis of the polarization features of the structure of reflected radar signals. The first of the presented methods allows us to estimate the main parameters of the signals of the onboard information meteorological system, received by onboard radar from meteorological objects (the area under study, filled with hydrometeors of different types), and based on the mathematical model of reflection of electromagnetic waves from hydrometers of a non-spherical form presented in the paper. The model allows calculating the polarimetric parameters of the reflected signal by approximating the non-spherical shape of the scatterers (hydrometers) by spheroid rotations and using the m odified Rayleigh formulas. The second of the presented methods describes the algorithm for detecting potential icing zones by identifying the types of hydrometeors based on the analysis of the difference between polarimetric informative parameters of the reflected signal of the onboard information meteorological system, taking into account the results of mathematical modeling and estimation of these parameters in the first of the presented methods in this thesis. The theoretical studies presented in the work are confirmed by experimental data, in particular, the results of practical measurements of clouds and precipitation by existing meteorological radar. The third method, described in this thesis, uses a mathematical apparatus of fuzzy logic to assess of icing degree of an aircraft. Also, in this work, existing methods of icing zones detection were analyzed, and new and more advanced methods were proposed to warn of the threat of icing before it began, taking into account the combination of factors such as the polarimetric parameters of the reflected signal, temperature, height, velocity, duration of stay in a danger zone, and others. The estimation of the reliability of these methods is given, and the recommendations for their implementation in the existing information systems of ensuring the safety of flights are given also.