1National Technical University “KPI”, Kharkiv, Ukraine
2Kharkiv National Technical University of Radio Electronics
On the Use of Acoustic and Radioacoustic Methods of PBL Remote Sensing for Assessment of Radiowave Propagation Conditions
In the article, there are considered the potentialities of the sodar-RASS complex created in Ukraine for remote measurements of meteorological parameters defining the height run of the air refractivity in the PBL. A new approach for the design of sodar-RASS equipment and principles of its operation for determination of main meteoparameter profiles, and hence of refractivity profiles, are considered. It is anticipated that this approach will be free of some shortages of sodar-RASS complexes being used nowadays.
National Aerospace University
1, Cosmonaut Komarov Avenue, Kyiv 03058, Ukraine
Differential Doppler Velocity: Radar Parameter for Estimating Turbulence Intensity
The differential Doppler velocity is one of the parameters that combines in itself both the Doppler and polarization measurements while scanning the meteorological precipitation with the help of a Doppler polarimetric radar. The Doppler measurements allow to get information about dynamic processes occurring in precipitation (raindrop velocity) and the polarimetric measurements allow to get an information about the shape and orientation of hydrometeors. When turbulence occurs, the raindrops are involved into motion and change their velocity and orientation. The investigation results for the dependence of the differential Doppler velocity upon the turbulence intensity are represented in this paper. Relationship between these parameters is shown both theoretically with the help of the developed model and practically after processing of the data obtained from the Doppler polarimetric radar.
A. Usikov Institute of Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura Str., Kharkiv 61085, Ukraine
Spatial Discrimination of Small Surface Objects against the Sea Clutter Background
We substantiate the principal possibility of using spatial periodicity of a signal reflected at sea surface to improve radar detection of the small above the sea objects. Using the suggested discrimination algorithms, the coefficient of improvement of object observability is estimated theoretically. Comparison with the results of numerical and full-scale experiments is made.
Donetsk Research Institute of Complex Automation, Donetsk, Ukraine
Comparative Analysis of the Quasi-Optimal Method for Detection of Software Defined Operation Frequency Tuning on the Basis of J-Correlation Signal Processing
The comparative analysis of outcomes of laboratory researches of a radio communications system JTIDS detection receiver with calculated parameters of the detection receivers realized by methods of a matched filtration, is carried out. Is shown, that the detection receiver fulfilled on base of a J-correlation signal processing, ensures to obtain the output signal-to-noise ratio exceeding the value determined in the theory of an optimum reception, as potentially possible.
Kharkov National University of Radio Engineering and Electronics,
14, Lenin Ave, Kharkiv, 61166, Ukraine
Increasing of the Efficiency of Signal Expansion within the Redundant Basis
The method of a signal expansion in the redundant basis is considered. This method is based on the minimization problem solution. Refinement in the method consisting in the numerical solution of the ODE’ system, describing the minimization problem is offered. The method under consideration makes it possible to rise the expansion speed by an order of magnitude.
Algorithm for Determination of the Volume of Steganographic Embedment by the Method of Statistical Analysis of the Histograms of DCT Coefficients of JPEG Format Images
V. Karazin National University of Kharkiv,
4, Svoboda Sq., Kharkiv, 61077, Ukraine
A Method for Determining Permittivity, Volume Characteristics and Hydratation of Aqueous Solution Components
A procedure of calculating permittivity of bound water, hydratation of substances, volume fractions of water solution compounds from measurement data on complex permittivity and the densities of solutions.
Institute of Engineering Industry Problem
2/10, Pozharskogo Str., Kharkiv, 61046, Ukraine
Permittivity Measurement Technique for Inhomogeneous Dielectric Materials
The new method is proposed to measure the average permittivity of inhomogeneous dielectric polymeric materials at millimetre-wave band. For practical implementation of the method the two-shoulder antenna with piecewise linear phase distribution of fields was designed. In the course of measurements the geometrical dimensions of antenna is varied; in so doing the phase jump is linearly associated with its dimensions.