V.F. Kirichenko and Yu.F. Logvinov
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
Space-Time Characteristics of Illuminated Sea Surface Areas Observed at Narrow Grazing Angles

Space-time characteristics of illuminated sea surface areas have been obtained by computer simulation. The case of backscattering at narrow grazing angles was studied. Comparison shows a good agreement of simulation results with experimental data.

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V. G. Gutnik1, G. P. Kulemin2, L. I. Sharapov1, and E. A. Goroshko2
1Institute of Radio Astronomy, National Academy of Sciences of Ukraine
4, Krasnoznamennaya St., Kharkov 61002, Ukraine

2A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
Intensity of Choppy Sea Radar Backscattering for Small Grazing Angles

An analysis of models of sea radio wave backscattering over the frequency range of 1 150 GHz has been carried out. The dependences of the normalized radar cross-section on the grazing angle and wind velocity have been considered. The influence of drop-spray fraction on the total radar cross-section and scattered signal fluctuations has been analyzed for the millimeter wave band.

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O. Bezvesilniy, G. Peters1, and D. Vavriv
Institute of Radio Astronomy, National Academy of Sciences of Ukraine
4, Krasnoznamennaya St., Kharkov 61002, Ukraine

1Meteorological Institute, University Hamburg,
Bundesstrasse 55,D 20146 Hamburg, Germany,
Estimating Cloud and Rain Parameters from Doppler Radar Data

Real-time mapping of the parameters of precipitating water clouds and rain using a vertically-directed Doppler radar is an important problem. In this paper, an algorithm based on an independent estimation of the droplet effective diameter and concentration is suggested. This approach differs from the Marshall-Palmer retrieval procedure that is based on a single estimated parameter, the radar reflectivity factor. It is shown that the Marshall-Palmer approach can provide good estimates of the averaged parameters, however is not suitable for producing the high resolution time-height maps of the parameters. The two-parameter retrieval algorithm under discussion was tested using the data obtained with the 36 GHz polarimetric Doppler cloud radar MIRA-36. The measurements data and their processing are presented. The suggested algorithm is applicable to real-time measurements with the vertically-directed Doppler radars.

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V.M. Kartashov
Kharkov National University of Radio Engineering and Electronics,
14, Lenin Ave, Kharkov, 61166, Ukraine
Estimation of Signal Parameters Scattered by an Acoustic Wave Packet

Singularities of algorithms for estimating parameters of the radio signal received in the systems of radio acoustic atmosphere sounding are considered. Determination of the atmosphere characteristics are carried out in accordance with the measurement results.

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O.V. Sytnik
IA.I. Kalmykov Center of Radiophysical Sounding of the Earth of National Academy of Sciences and National Cosmic Agency of Ukraine,
12, Academician Proskura St., Kharkov, 61085, Ukraine
Algorithm for Detection and Identification of Low Doppler Target

The method of detection and identification of a low Doppler target under conditions of intensive disturbances having fluctuating character is investigated in this article. The proposed algorithm for calculating the estimations of the target spatial position and the Doppler frequency translation of a signal reflected from the target is an optimum from the standpoint of the maximum of likehood. The algorithm was based on the principle of the combined processing of signals from spaced sensors in order to obtain the optimum estimations of signal parameters. The analysis is carried out both in the spectral and in the time domains which makes it possible to extract a maximum amount of information about the object under investigation with disturbances of different character and level. The results of the algorithm modeling are presented, the characteristic features of its performance in actual practice are discussed.

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N.V. Barkhudaryan, S.E. Vazhinsky, V.A. Vasilets, A.Z. Sazonov, and O.I. Sukharevsky
Kharkov Military University, 6, Svoboda Sq., Kharkov, Ukraine, 61043.
Mathematical Simulation of the Bearing Process in the Near Zone of a Complex Extended Object

The methods which makes possible to calculate errors in taking bearing to an aerodynamic object of a complex shape are presented. The direction finder is located in a near zone of a scatterer. It is shown that the errors have been mainly caused by distortions in the amplitude-phase distribution of a field in the receiving antenna aperture. As the distance to an object decreases, angular deviations increase and may become considerable. The results of calculations of amplitude-phase distributions of the field in the aperture and the corresponding bearing errors for an airplane with a maximum cross size of 20 meters are represented.

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V.P. Burmaka, L.S. Kostrov, and L.F. Chernogor
V. Karazin National University of Kharkov,
4, Svoboda Sq., Kharkov, 61077, Ukraine
Statistics of Signals of the HF Doppler Radar Sensing the Bottomside Ionosphere Disturbed by Rocket Launches and Solar Terminator

The statistical analysis of the variations in the Doppler spectra resulting from forty-three rocket launches has revealed four groups of apparent velocities of disturbance transfer: 0.5?0.8, 1?6, 7?9, and 15?20 km/sec. They are related to acoustic-gravity, slow magnetohydrodynamic, magnetogradient, and possibly gyrotropic waves.
The analysis of thirty-one events of the moving solar terminator has made it possible to obtain the statistics of the Doppler spectra variations (variations in the mean Doppler shift of frequency, duration of ionospheric response, predominant time period, and the amplitude of the central frequency of quasi-periodic disturbance).

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L.I. Netikova
Kharkov National University of Radio Engineering and Electronics,
14, Lenin Ave, Kharkov, 61166, Ukraine
Method of Calculation of Electromagnetic Radiation Power Absorbed by a Human Body during Operation of Subscriber Offices

Simulation of the field of a subcriper office in the immediate to a user's head is considered by means of FDTD (Finite-Difference Time-Domain) method.

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