The State primary standard of relative humidity, molar (volume) fraction of water, dew point/frost temperature units GET 151-2014 improvement was carried out in order to expand the numbers and ranges of reproducible values and improve its functionality. As a result of the improvement, a set of reference generators was developed and introduced into the State primary standard, reproducing the dew/frost point temperature and the hydrocarbon condensation temperature at high pressures of the working gas. The description of the National primary standard of relative humidity, molar (volume) fraction of water, dew/frost point temperature, hydrocarbon condensation temperature units GET 151-2020 and its complex of reference generators, which implement the reproduction of units of dew/frost temperature and hydrocarbons condensation temperature units, is presented, taking into account the info fencing factors according to working gas pressure. The metrological characteristics of GET 151-2020 have been studied. A budget of the measurement uncertainty has been compiled when reproducing the dew/frost point temperature and the hydrocarbon dew point temperature. The State verify action scheme for measuring gas humidity and hydrocarbon condensation temperature was developed and approved. Topical issues of ensuring the uniformity of measurements in the fi led of hygrometry have been resolved. The tasks of metrological support of means for measuring the dew point temperature and the condensation temperature of hydrocarbon gases at high pressures of the working gas have been implemented. The results obtained will be useful in creating an experimental base for studying the physical properties of technical and natural gases and approving state reference data in a wide range of pressures and temperatures of the working gas.

In the second half of the 20th century, for the fi rest time, data were obtained that indicated anomalies of Hubble's redshift law. Their author was the American astronomer Helton Arp. He also hypothesized the origin of quasars as ejections from galaxies with active nuclei and was a proponent of the Big Bang theory. The latter circumstance caused numerous criticism of the results obtained by him. However, by the end of the 20th century, redshift dipole anisotropy and anomalies of Hubble parameter estimates were discovered in the Local Group of galaxies. The increasing distribution of these estimates for SN Ia supernovae relative to the estimates of the Hubble parameter based on measurements of microwave background radiation when interpreting measurement data within various cosmological models and the redshift anisotropy in 2016 caused a discussion about the crisis in cosmology. Wendy Freedman and Adam Riess started it. An brief overview of the discussion materials is given, and the problem of identifying the scale of cosmological distances is considered as a calibration problem. As a result of its solution, the redshift anisotropy dipole of supernovae of type SN Ia was revealed as reference points of the photometric distance scale. The dipole has a maximum in the region of the north galactic pole, and a minimum in the region of the south pole. The opposite orientation of the redshift anisotropy dipole for quasars has become new aspect of the problems of the cosmological distance scale.

The problem of the dynamic measurement error estimation and compensation is considered. This type of error is determined by two components. The fi rest one is due to dynamic properties (inertia) of a sensor. The second one is due to the presence of an additive noise at the sensor output. The dynamic error reduction consists in simultaneous correction of these two components. The structure of the measuring system with the dynamic measurement error estimation is developed. Correction of the dynamic error is carried out by simultaneous restoration and fi altering of the measured sensor input signal. The structure of a special filter with a preliminary correction of the sensor transfer function to a form convenient for further processing of the measured signal is proposed. Further signal processing consists in the iterative application of a restoring FIR fi later with the dynamic error estimation. A computer simulation of the proposed measuring system for the second-order sensor was carried out. Optimal (in the sense of minimization of the dynamic error estimation) orders of the restoring filter are obtained for input signals of various types in the presence of an additive Gaussian noise at the sensor output. A decrease in the dynamic error estimation based on the proposed structure of the dynamic measuring system is demonstrated. The application fi eld of the results obtained is the measurement of fast-changing processes, when the dynamic component of the error, caused by dynamic properties (inertia) of the sensor, as well as additive noises at its output, is dominant.

The issues of metrological support of measuring instruments of two-dimensional spatial distribution (profile) of the refractive index unit of solid substances are considered. A reference setup has been developed, which is included in the State primary standard of the refractive index unit GET 138-2021. The composition, principle of operation, and main metrological characteristics of the reference setup, which is based on a digital interferometer for measuring the two-dimensional spatial distribution (profit le) of the refractive index of thin sections of preforms of graded glass fibers, are presented. The reference setup from GET 138-2021 for the first time ensures the uniformity of measurements for measuring instruments for the refractive index profile, the so-called optical analyzers of preforms and the fiber itself, which are used in the production of optical glass fibers. The results of experimental studies of GET 138-2021 in terms of reproducing the two-dimensional spatial distribution of a refractive index unit are presented.

An urgent problem of remote monitoring of scattering particles in the lower atmosphere is the development of methods for obtaining information about the microstructure of the scattering layer from the measured backscatter signal. The main parameters of the microstructure of the surface layer of the atmosphere include the concentration and cross-sectional of particles. In lidar sensing, the main measured quantities are the backscatter coefficient and the extinction coefficient. For single-frequency lidar sounding, these coefficients can be associated with an equivalent scattering medium consisting of monodisperse particles. This makes it possible to interpret the backscatter coefficient and extinction through the microstructure of an equivalent medium. In lidar sounding, the quantity directly related to the transverse particle size is the angular size of the halo around the beam propagating in the scattering medium. On the example of a two-position probing scheme, methods for measuring the angular size of the halo around a beam that has passed through a scattering screen are considered. The diffusing screen is an opaque plane with holes whose projections are the images of particles. It is shown that if the angular size of the beam passing through the screen is doubled, then the measurement scheme will be optimal. This can be achieved either by choosing a linear magnification, according to which the images of particles on the screen are created, or by moving the screen along the probing line. The implementation of these methods makes it possible to describe the polydisperse and non-spherical particles contained in the surface layer of the atmosphere through the cross section of equivalent particles. It becomes possible to use remote methods in the problem of monitoring the surface layer of the atmosphere.

Methods for assessing the sensitivity characteristics of a vibration induction converter designed to control the discontinuity of the surface of objects when they are magnetized by an applied constant field are described. Based on the analysis of the mathematical model of the output signal of the converter, analytical expressions are obtained for the conversion coefficients of the rate of change in the magnetic field strength and acceleration along the coordinate of the vibration displacement of the converter in the EMF induction coil. The methods of experimental estimation of conversion coefficients are given and the high convergence of calculated and experimental estimates is shown. Based on the formulated conditions for the detection of magnetic field anomalies arising on the defective surface areas and the known values of the conversion coefficients, calculated ratios were obtained to estimate the sensitivity thresholds of the converter according to the orthogonal components of the magnetic field strength distribution. As a result of the experimental verification, the adequacy of the calculated and experimental estimates of the sensitivity thresholds was confirmed. Recommendations are given on the application of computational and experimental methods for assessing the sensitivity characteristics of a vibration induction transducer.

A two-stage approximate method for reconstructing the phase of the signal spectrum from the amplitude of the spectrum is proposed. At the first stage, the signal is reconstructed by a numerical method (in one-dimensional and two-dimensional cases) from the known modulus of the spectrum; at the second stage, the spectrum of the reconstructed signal is determined and the phase of the spectrum is calculated. Signal recovery from a known modulus of the spectrum is modeled by a nonlinear Fredholm equation of the first kind, which is solved using the spline-collocation method with splines of zero and first orders and a generalization of the continuous method for solving nonlinear operator equations. Model examples of restoration of one-dimensional and two-dimensional signals are given. The accuracy of signal reconstruction under various perturbations in the input signals and in computational circuits has been studied. The absolute and relative values of spikes at the leading and trailing edges of the signals are estimated. Methods for suppressing the Gibbs effect are considered. The proposed method can be used in optics, astrophysics, biology, and medicine.

The following problem is considered in the underwater acoustic. At the same time the location of the hydrophone acoustic center must be known respect to the reference point. A method is proposed for determining the position of the acoustic center of a hydrophone relative to a selected reference center. The scheme of the experiment to determine the position (displacement) of the acoustic center of a hydrophone relative to the geometric center of the active element contour is described. The results of the experiment for different types of hydrophones are presented and the sources of measurement uncertainties are discussed. It is shown that taking into account the displacement of the acoustic center makes it possible to improve the accuracy of the phase calibration of hydrophones. The proposed method can be used in the field of the underwater measurement of the sound pressure receiver sensitivity.

The problem of determining the accuracy of an autoregressive model of a speech signal is considered, and a method for measuring the accuracy index in the sliding observation window mode is proposed. As an indicator of the accuracy of the autoregressive model, a modified value of the COSH-distance (functions of the hyperbolic cosine) relative to the eponymous (one-phoneme) Schuster periodogram was used as a reference spectral sample. To study the possibilities of the proposed method, a full-scale experiment was set up and carried out, in which the object of study was a set of autoregressive models of different orders. These models were obtained by Berg's method for the vowel sounds of the controlled speaker's speech. According to the results of the measurements for each vowel, the optimal values of the autoregressive order and the corresponding optimal autoregressive model were found. It is shown that this optimization made it possible to increase the accuracy of the autoregressive model of the speech signal by more than 60 %, depending on the sound of the controlled speaker's speech and the characteristics of his vocal tract. The results obtained are intended for use in automatic processing and digital speech transmission systems with radical data compression based on linear prediction coefficients.

The article presents information on the development of a reference method of measurements (RMM) the mass fraction of ethers of orto-phthalic acid (dimethyl phthalate, diethyl phthalate, di(n-butyl)phthalate, benzylbutyl phthalate, di(2-ethylhexyl)phthalate and di(n-octyl)phthalate) in polymer matrices based on polyvinyl chloride by gas chromatography/mass spectrometry with isotopic dilution. The research materials of each stage of the measurement procedure and the parameters of their optimization in terms of improving the accuracy of the measurement results of the RMM are presented. The sources of uncertainty are studied and the contributions of all components to the total standard uncertainty of the RMM measurement results are minimized. Metrological characteristics of RMM have been established: the measurement range is from 10 mg/kg to 5000 mg/kg, the standard deviation (SD) under repeatability conditions is 2 %, the SD under intermediate precision conditions is 3 %, the relative extended uncertainty is from 6 to 8 %. The results of the key international comparisons CCQM-K133 “Phthalate esters in Polyvinyl Chloride (PVC)” are presented as an objective confirmation of compliance with the RMМ.