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Practical application of the radio-holographic method for measuring the characteristics of antennas, especially when conducting acceptance testing of systems, requires an adequate assessment of the errors in the recovery of long-range characteristics. These errors appear to be a superposition composed of various sources, having different nature, different time characteristics and different degrees of influence on the final result. The purpose of this work was the development of a practical technique for determining the influence of random errors in measuring the amplitude-phase distribution of the field of the antenna required for the accuracy of restoring long-range characteristics (primarily the antenna pattern) of the antenna, the proposed technique being based only on processing the experimental results obtained with this measuring complex.A practical method for determining the influence of random errors in measuring the amplitude-phase distribution of the field of the antenna under study on the accuracy of restoring its long-range characteristics (primarily the directional pattern) on the basis of correlation and spectral analysis has been developed and experimentally confirmed. The main advantage of the developed method in comparison with the use of mathematical modeling is that the estimation of the accuracy of the reconstruction of the directivity diagrams is based on the results of processing experimental data obtained on a specific measuring complex and does not a priori impose any preliminary requirements on the statistical parameters of errors. The developed procedure for estimating the influence of random errors can be used to develop a methodology for metrological certification of measuring systems as measuring instruments.

Directional patterns measurement of antennas is carried out by the methods of far and near zone. Measurements in the far zone are straightforward; however they have a number of disadvantages. Near zone measurement methods are free from measurement shortcomings in the far zone, but it requires complex and expensive equipment for its implementation.Earlier, the authors have developed a concept of hardware and software modular design complex to determine antenna system characteristics as per measurements in the near zone. This concept assumes creation of a universal measuring complex to investigate various types of antenna systems with any type of measurement surface (plane, cylinder, sphere) in order to solve a wide range of applied problems. The purpose of this work lies in practical implementation of a variant of this measuring complex for measurement along the plane and determination of its metrological (hardware and software) capabilities.A working experimental sample of hardware and software complex for measuring the characteristics of antenna systems that realizes a radio-holographic method for measuring along a plane has been developed, created and practically tested. A preliminary estimation of errors in amplitude and phase measurements in the dynamic range of 45 dB and a comparison of the characteristics of several types of antennas measured in far and near zones have been made. Algorithms have been developed, a software for processing, storing and graphical display of measurement results has been created.

Measuring the amplitude-phase distribution of the radiation field of complex antenna systems on a certain surface close to the radiating aperture allows solving the problem of reconstructing the free-space diagram in the far field and also helps in determining the influence of various structural elements and defects of radiating surfaces on formation of directional diagram. The purpose of this work was to develop a universal hardware-software complex of a modular design aimed for determining the characteristics of wide range of antenna systems in respect of measurements of the amplitude-phase distribution of the radiation field in the near zone.The equations that connect the structure of radiation fields of the antenna system at various distances from it in planar, cylindrical and spherical coordinate systems as well as structural diagrams of the hardware part of measuring complexes have been analyzed.As a result, the concept of constructing a universal hardware-software complex for measuring the radiation field of various types of antenna systems with any type of measurement surface for solving a wide range of applied problems has been developed. A modular structure of hardware and software has been proposed; it allows reconfiguring the complex rapidly in order to measure the characteristics of any particular antenna system at all stages of product development and testing, and also makes the complex economically accessible even for small enterprises and organizations.