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The article deals with the noise analysis of magnetic sensors using Allan variance. In comparison with the standard variance, based on the variations around the average value, Allan variance provides a measure of the behavior of the variability of a quantity as it is averaged over dierent measurement time periods, which results in a better convergence and the possibility to distinguish types of noise directly. A signicant advantage of this method is that there is no need of any transformations and according to the IEEE recommendation the Allan variance approach is the preferred method for stochastic error identication and the noise type determination in inertial sensors (accelerometers and gyroscopes). Considering that magnetic sensors become even more often a part of inertial measurements units, the goal of this article is to prove that the method using the Allan variance analysis can be very successfully applied also for noise analysis in magnetic sensors.

This article presents a novel concept for a highly accurate and simple two-port vector signal analyzer. A current phase ratio measurement method is defined for one independent external signal with a restriction of the measuring range ±90 or ±180º. The article presents a new way of phase ratio evaluation of two independent external signals with precise phase determination in a wide range from 0º to 360º. The new functional blocks of the analyzer circuit element act as a four-position radio frequency (RF) switcher and an algorithm for phase determination is presented. Practical application and verification of the results achieved are demonstrated by measuring the phase directional radiation pattern of a complex object such as an aircraft fuselage.

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The paper deals with approaches in modeling of a complex electro-hydro-mechanical system. The proposed system is a fuel metering device that is a non-linear system with hysteresis and transport delays. The classical methods of modeling demand knowledge of mechanics and inner structure of the researched object. The paper deals mainly with experimental data driven methods of modeling. The created models will serve as a basis for controller design to employ the fuel metering device into the digital control system of a small turbojet engine MPM-20 .