Telecommunications and Radio Engineering, 65(1)

G.А. Аlexeev and М.V. Belobrova
A. Usikov Institute of Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura Str., Kharkiv 61085, Ukraine
Recovering of Structural Profile of the Tropospheric Refraction Index upon Field Correlation Functions

The analysis of the method for finding numerical solution to the inverse problem of radio translucence of the turbulent stochastically heterogeneous troposphere by the spherical radio wave based on transition to the equation with a self-adjoint operator and consequent application of the Bakushinskiy method of regularization is performed. It is demonstrated that at optimal parameters of the regularizing algorithm the method allows to recover the height profile of the structural characteristic of troposphere refraction index upon transverse spatial correlation functions of amplitude fluctuations with a rather high accuracy within a wide range of states of the turbulent stochastically heterogeneous troposphere.

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V.I. Antyufeev, V.N. Bykov, and V.V. Chmil
Joint Research Institute for the Armed Forces
OJSC Saturn Research and Production Association, Kyiv, Ukraine
Likelihood of Correct Image Registration in the Correlative-Extremal Navigation Systems

Derived in [2] formula for probability of correct image registration assumes a hit of the coordinates estimation formed by the algorithm in the vinicity of the set size of true matching point. Good agreement of results of the algorithm statistical tests with the theoretical data is obtained.

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Raul E. Sanchez-Yanez, Horacio Rostro-Gonzalez, and Victor Ayala-Ramirez
Universidad de Guanajuato FIMEE, Tampico 912,
Colonia Bellavista, Salamanca, Guanajuato, 36730 MEXICO
Image Approximation from Scattered Pixel Evidence: A Fuzzy Approach

A fuzzy approach for image approximation is discussed. The image is considered as a two input-single output Mamdani-type fuzzy model. The pixel position is the input while the output is the pixel intensity. This fuzzy model is completely obtained from scattered pixel evidence. Such approach can be used for function approximation tasks or as a model identifier from scattered numerical evidence.

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Andres Frias-Velazquez and Rene de Jesus Romero-Troncoso
FIMEE, Universidad de Guanajuato,
Tampico 912, Col. Bellavista, 36730 Salamanca Gto., M?xico
Algorithm for Convergence Criteria Simulation on LMS Adaptive Filters

A standard algorithm for LMS-filter simulation, tested with several convergence criteria under system identification configuration is presented in this paper. Establishing a reliable convergence criterion is mandatory in order to properly design an LMS filter and so avoid instability problems that may arise if both quantization effects and interdependency relationship among learning curve behaviors are not taken into account. Simulations performed under Matlab show remarkable differences between convergence criteria proposed by several authors and one presented in a previous work derived from a complete learning curve analysis.

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Oscar Ibarra-Manzano and Luis Arceo-Migue
Guanajuato University, FIMEE, 36730, Salamanca, Gto, Mexico
Measurements and Estimation of the TIE of a Crystal Clock Using an Unbiased Fir Filtering Algorithm

An unbiased finite impulse response (FIR) filtering algorithm is investigated for the GPS-based measurements of a local crystal clock. The algorithm is examined for the time interval error (TIE) measurements in presence of the uniformly distributed sawtooth noise induced by the multichannel GPS timing receiver. Based upon, we show that the unbiased FIR estimates are consistent with the reference (rubidium) measurements and fit them better than the standard Kalman filter.

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Cruz A. Longoria-Mendez, Victor Ayala-Ramirez and Raul E. Sanchez-Yanez
Universidad de Guanajuato FIMEE, Tampico No. 912,
36730 Salamanca, Gto. MEXICO
Comparison of Two Corner Detectors for their Application to a Tracking Task

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V.M. Kontorovich and A.Yu. Nikitin
Institute of Radio Astronomy, National Academy of Sciences of Ukraine
4, Krasnoznamennaya Str., Kharkiv 61002, Ukraine

A. Usikov Institute of Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura Str., Kharkiv 61085, Ukraine

On the Velocity of Beam Generating Fast-Drift Radio Bursts in Solar Corona

It is shown that the data on drift velocities of III type radio bursts and the velocities of II-type HB-burst components (of "herring-bone" structure) are not contradictory to the views of free electron-beam expansion in the solar corona if the low-speed Coulomb electron scattering is taken account of. The findings of the kinetic theory suggest that the characteristic average drift velocity is largely dependent upon the height of beam initiation and, consequently, upon the plasma density at the point of its origin. This, to a large extent, results in the difference between the velocities of the beams generated by chromospheric bursts and the beams being produced at shock wave fronts in the solar corona.

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A.M. Gokov
V. Karazin National University of Kharkov,
4, Svoboda Sq., Kharkiv, 61077, Ukraine
On Some Electrical Characteristics of the Atmosphere in the Conflagration Regions and Atmosphere-Ionosphere Electrical Interaction

Main characteristics of large-scale fires are considered. On the basis of a preliminary model for volumetric average-density distributions of the smoke aerosol, formulae for estimating disturbances in electrical characteristics of a near-Earth atmospheric layer are given. A conjectural model for atmosphere-ionosphere interactions is presented, main mechanisms of disturbances transferred from the lower atmosphere into the ionosphere and magnetosphere are briefly analyzed, and probable ecological effects are discussed.

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O.V. Sytnik, A.I. Logvinenko, and G.I. Klochko
A.I. Kalmykov's Center of Earth radiophysic sounding,
National Academy of Sciences and National Space Agency of Ukraine,
12, Ak. Proskury Str., Kharkiv, 61085, Ukraine

An Ultrasonic Method for Heat Process Investigation in Living Tissues

The study is devoted to a non-invasive ultrasonic method of detection and identification of heat transmission in living tissues. The suggested method of temperature variation registration in internal layers of living tissues while local heating is optimal in terms of highest likelihood. The estimation algorithm of temperature gradient spatial distribution is based on measuring the difference of phases of low-power ultrasonic signals reflected by tissues heterogeneities and evaluating the temperature differentials by variations in the received signal delays. The properties of signals reflected by various sorts of tissues have been investigated; the ultrasonic velocities have been estimated for various temperatures and salt content of the samples. The key relevant factors for errors in measurements have been analyzed. The structure of a heat transmission analyzing device for living tissues has been designed. The digital part of the device has two channels, a phase and an amplitude one. The phase channel delivers the temperature gradient estimations, the amplitude one has an auxiliary function of detecting the localized heterogeneities and determining their spatial characteristics. The paper presents the results of the algorithm modeling; its implementation under real interference situation is discussed.

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