Maslovskiy A. Radar characteristics of complex shape on-ground objects based on reflection measurements from local areas

The dissertation is devoted to solving the actual scientific problem of improving the method of calculation and measurement of radar characteristics of a complex shape object. The characteristics of electromagnetic waves scattering on the objects, which are located on the underlying surface were investigated. In dissertation the analysis of experimental and theoretical methods for secondary radiation estimation of complex form ground objects is carried out. Existing methods of measuring of the radar cross section in a far zone are considered. A brief analysis of technical means for measuring radar characteristics of objects with complex surface is given. On the basis of the review of the advantages and disadvantages of field measurements of the radar cross section of complex objects, it was concluded that there is a need to study secondary radiation of complex ground object on the basis of a decomposition method. Based on the research carried out in the dissertation it is possible, from RCS calculations with a big angle step, to drive conclusions about the average RCS for the object and to determine the confidence intervals in which this average value with a given probability will lie. In particular, we can conclude that in order to obtain a relative error no greater than for each of the models analysed in the work should choose an angle step of not more than 3º. Based on the results obtained in the near-field of the object, a decomposition method for calculating the secondary radiation of the ground object is presented. The calculation of secondary radiation of a tactical armored wheeled car model (TWAC) has been calculated by decomposition method. The verification of theoretical calculations was performed by comparing the locations of the areas with the largest RCS values, which were obtained experimentally, and by means of numerical simulation. Comparison of the locations of the most reflective areas of the surface showed a coincidence of the locations obtained in the experiment and calculated theoretically, by 75%. In the dissertation work the method of partial coverage of the object ("camouflage") was developed with the radio-absorbing material in such a way that the value of the average RCS of the object in the given angle of irradiation was as close as possible to the average RCS of the "shaded" by the object area of the underlying (background) surface. Thus, the developed method makes it possible to make the object as completely invisible ("non-contrast") for radar surveillance devices.