Distributed detection basis on using soft decision scheme both in local sensors and in fusion center

The paper considers distributed detection problem basis on using soft decision scheme both in the local sensors and in the fusion center (FC). The algorithm for making soft decisions when receiving data from local sensors in the fusion center and its performance characteristics, which are necessary for the formation decision fusion rule, are presented. The dependencies of the total error probability on the energy parameter taking into account signal-to-noise ratio at the level of local sensors and the channel’s signal-to-noise ratio are given. The gain of the fusion rule basis on the aggregation of soft decisions in the FC when receiving data about soft local decisions, in efficiency compared to hard fusion rule.

Method for measuring the azimuth of an aerial target for a meter-range radar

The purpose of the study is to develop a new method that increases the accuracy of measuring the azimuth of an air target for stationary radars of the meter range of radio waves with a fixed antenna array and a small number of antenna elements. For this, the known methods are considered and their disadvantages are revealed. The new method proposed by the authors uses a digital radiation pattern with a fast Fourier transform after intra-pulse processing of signals from the receiving elements of the antenna array at a given frequency. To refine the azimuth, an inverse fast Fourier transform is used, followed by signal processing and repeated measurement for each target with a small step. Calculations and test results are presented. Comparisons of statistical estimates of the mean and standard deviation of azimuth measurement tests by various methods are presented. The scientific novelty and directions for further development of the topic with the use of the results obtained have been established.

Wideband antenna with circular polarization for GLONASS system

The article analyzes the requirements for antennas used in modern anti-jamming navigation equipment of the consumer of GLONASS. Some options and their disadvantages are considered. Presents the results of the development, computer modeling and experimental study of a breadboard circular polarization antenna layout for the GLONASS system. Tests were carried out for both a single antenna layout and a two-element antenna array. Experimental frequency dependences of such parameters as matching, isolation, gain and axial ratio, as well as radiation patterns at key frequencies are given. The achieved bandwidth covers the L1 and L2 ranges of GLONASS. Based on the results obtained, a conclusion was made about the possibility of using the developed antenna as a single element of adaptive antenna arrays of the GLONASS system.