A scanning device for a space-based environmental monitoring system has been investigated. The main attention is paid to the study of the parameters of the angular motion of the mirror of the scanning device, the uniformity of rotation of which largely determines the quality of the image of the Earth's surface. The principle and results of measuring the parameters of the mirror rotation carried out in a wide angular range are considered. The measurements were performed using a dynamic goniometer-autocollimator, which has been calibrated at the State Standard of Plane Angle Unit GET 22-2014. The repeatability of the average angular velocity of the scanning device mirror and the repeatability of the initial scanning angle are calculated. Nonstationarity in mathematical expectation and variance in random deviations of the angular motion of the mirror from the linear law of scanning is noted. The use of wavelet analysis revealed the frequency of excitation of oscillations in the low-frequency region of the spectrum. The possibility of using the a dynamic goniometer-autocollimator for measuring not only the angular position of the scanning device mirror, but also the angular velocity is shown.

The problem of developing a thermal compensation system in quantum frequency standards based on the effect of coherent population trapping is considered. The development of such a system significantly reduces the temperature coefficient of frequency, the value of which is an order of magnitude higher than in rubidium frequency standards. One of the ways to reduce the temperature coefficient of frequency is temperature compensation. A method of thermal compensation based on the Zeeman effect for the shift of the actual frequency is proposed. A method for determining the minimum value of the magnetic field at which there is no influence of magnetosensitive resonances on the reference resonance is considered. The results of the operation of the quantum frequency standard before and after switching on the thermal compensation system are presented.

The article deals with one of the important tasks of modern flow measurement, which is related to the measurement of the flow rate and the amount of wet gas. This task becomes especially important when it becomes necessary to obtain information about the separate amount of the dry part of the gas that is contained in the form of a mixture in the wet gas stream. The paper presents the principle of operation and structure of the invariant system for measuring the flow rate of wet gas, which is based on the combined use of differential pressure flowmeters and Coriolis flowmeters. The operation of the invariant wet gas flow rate measurement system is based on the simultaneous application of the multichannel principle and the partial flow measurement method. Coriolis flowmeters and the differential pressure flowmeter are used as the main elements of the system. The proposed measurement system does not off er applications for gases with abundant drip humidity. The article provides information about the test results of the proposed invariant system. The estimation of the metrological characteristics of the invariant system when measuring the flow rate of wet gas is given. The obtained test results of the invariant wet gas flow rate measurement system are relevant for natural gas production, transportation, and storage facilities.

In industrial technological processes associated with the heating of the processed material by microwave radiation, it is necessary to measure the temperatures of objects. Methods for measuring temperatures in the fields of technology using microwave heating systems are considered. The main possibilities, disadvantages and limitations of the used contact and non-contact (optical) measurement methods are determined. The requirements for temperature measurement systems under conditions of exposure to strong electromagnetic fields are listed. The possibilities of the spectral pyrometry method are especially noted.

A simple algorithm for reliably determining the Q-factor of an open dielectric resonator made of a material with a tgδ less than 0.0001 in the shielded region is presented, based on measuring the parameters of an electromagnetically coupled system of bulk metal and open dielectric resonators. The analytical substantiation of the considered method for determining the Q-factor of an open dielectric resonator in electrodynamic and electrotechnical representations is carried out. The variants of the influence of the metal volume on the effective Q-factor of an open dielectric resonator depending on its electrophysical characteristics are considered. The factors affecting the effective Q-factor of an open dielectric resonator obtained using this measurement method are evaluated, and the range of expected measurement errors is shown. The advantage of the method for determining the Q-factor of an open dielectric resonator is the high accuracy of the obtained analytical ratios for determining the Q-factor, the absence of increased requirements for the accuracy of the measurement sections and the quality of the internal surfaces of the metal resonator, the simplicity of the measurement process, based on the use of ordinary equipment and element base.

This work describes the new approach to the improving of the accuracy of the bridge impedance measurements. By this approach the bridge balance in wide impedance range uses the control of the phases of the aggregate of the cardinal signals only. The optimal structure and algorithm of the control of this aggregate of the cardinal signals is determined. Using this approach accurate impedance meters with low size and price could be developed. In the limit, this approach gets us possibility to develop fully integrated impedance meters. Report shortly describes universal impedance meters with phase control, their balance and calibration algorithms.

This paper is discussed two methods for measuring the bistatic scattering characteristics of flat samples of the material. The experimental studies and numerical simulations of the dependence of the specular reflection coefficient on the incident angle of wave on a flat material sample carried out in the bistatic scheme of the experiment (rotation of the receiving and transmitting antennas) and in the monostatic scheme using a dihedral corner reflector (rotation of the object). Measurements for the magnetodielectric flat sample were carried out in ITAE RAS on two test facilities with the corresponding scheme of the experiment. To identify the errors of the methods used, we carried out numerical simulations of the measurement of the specular reflection coefficient of the sample under test by the method of integral equations (method of moments) in the FEKO program in the formulation of two experimental schemes. The obtained results were compared with each other and with the results of analytical calculations of the specular reflection coefficient carried out using the Fresnel formulas when considering an infinite flat layer of material. These calculations make it possible to compare the methodical errors in measuring the reflection coefficient in the two considered experimental schemes. It was shown that the results of the measurements using the corner reflector give methodical errors (deviations from the analytical calculation) by 1–2 dB more than the measurements on the bistatic facility. The results of experiments and numerical simulations are in agreement with each other. The conclusions obtained in this work are applicable to any experimental facilities for the study of planar materials.

A theoretical and experimental study of methods for measuring the resonance frequency from the amplitude-frequency and phase-frequency characteristics of the resonator (amplitude and phase methods, respectively) has been carried out. In this case, digital frequency scanning was used to determine the resonant frequency. On the basis of the theory of probabilities, analytical expressions are derived that describe the dependences of systematic and random errors on the position of the resonance frequency in the interval between the nearest discrete frequencies, as well as on the noise level. The reliability of the derived expressions was confirmed in the course of a virtual experiment with a computer model of the resonator. It is also shown that the errors of the amplitude and phase methods for the noise level, at which no more than two discrete frequencies are recorded, practically coincide. However, if more than two discrete frequencies are recorded, then the indicated errors differ significantly, which is demonstrated using the experimental graphs. In this case, the errors in measuring the resonance frequency by the phase method practically do not depend on the frequency tuning step with a decrease in this step and linearly depend on the phase noise level. When measuring the resonance frequency by the amplitude method, the errors decrease with decreasing frequency tuning step, and for this case, an empirical formula is proposed for the dependence of systematic and random errors on the frequency tuning step and the amplitude noise level. The research results can be used in the construction of digital resonance sensors.

Methods for determining the height of sea waves, which are relevant for maritime navigation, have been investigated. The measurement of the height of sea waves by the method of radar sounding by polarization-modulated signals is considered. The energy and spectral characteristics of the radar signal reflected by the sea surface at low angles of incidence are described. An algorithm for calculating the average wave height based on the results of measuring the polarization anisotropy of the specificeffective scattering surface of the sea area is considered. The relation of the average frequency of the amplitude fluctuations of the reflected radar signals with the sea waves is given. The spectral characteristics of radar signals reflected by the sea surface when irradiated with polarization-modulated signals are analyzed. The procedure for forming an effective statistical estimate of the average wave height based on the results of spectral measurements is considered. The errors of the generated estimates of the wave height associated with the measurement errors of the polarization anisotropy of the effective scattering surface and the average frequency of the envelope of the amplitude fluctuations caused by the Doppler effect are analyzed. The results of experimental measurements of the spectra of the amplitude fluctuations of the envelope of the reflected signals at different states of the sea surface are presented. The analytical dependence of the polarization anisotropy of the effective sea scattering surface on the irradiation angle relative to the wave propagation direction is given. A comparison of estimates of the height of sea waves obtained from radar sounding and meteorological observation data is carried out.

The problem of early diagnosis of one of the most dangerous malignant neoplasms of the skin – melanoma is considered. A model for identifying the structural elements of lines in digital images of skin neoplasms in oncodermatology has been developed. The model is based on adaptive binarization of the original digital dermatoscopic image of skin neoplasms and subsequent operations of dilation, erosion, skeletonization and filtering of false fragments of lines. Test dermatoscopic images of skin neoplasms are visually divided into four groups to conduct the experiment. The optimal parameters of image processing of four groups for the model of selection of structural elements – lines – are experimentally established. The experimentally determined accuracy of the selection of lines was 95 %. The work is the result of interdisciplinary cooperation between dermatologists of the Central Medical Academy of the Presidential Administration of the Russian Federation, the Medical Institute of the Peoples' Friendship University of Russia and specialists in the field of information and measurement systems of the Engineering and Physical Institute of Biomedicine of the National Research Nuclear University “MEPhI”. The proposed model can be used in the development of computer systems to support medical decision – making in the diagnosis of skin melanoma – a dangerous malignant neoplasm.