Felix J. Yanovsky

Retrieval of information about turbulence in rain by using Doppler-polarimetric Radar

This paper considers new possibilities of turbulence intensity retrieval by using Doppler and Doppler-polarimetric radar sounding. Peculiarities of microwave scattering on moving droplets of different size and shape underlie new methods that are introduced, discussed, and checked by using radar data

Inferring microstructure and turbulence properties in rain through observations and simulations of signal spectra measured with Doppler–polarimetric radars

Doppler radars are able to measure important parameters of the target velocity. In contrast, polarimetric radars are very sensitive to features of the target shape and orientation relative to the radar beam direction. This chapter describes a novel Doppler–polarimetric approach to radar remote sensing. The combination of the Doppler ability and polarization diversity in the radar technology enables more comprehensive investigations of objects and phenomena in radar coverage. The discussion is adapted to the case of atmospheric remote sensing. A special case of cloud and precipitation observations is considered in greater detail. Mathematical models of signals and spectra of Doppler–polarimetric returns are discussed. It is demonstrated (theoretically, by simulation, and by real data processing) that important parameters of dynamic characteristics and microstructure of meteorological objects can be retrieved from Doppler–polarimetric observations. These results lead to new interesting and important applications like turbulence intensity measurement, drop size distribution estimation, recognition of type of scatterers, detection of hail zones, etc.

Phenomenological models of Doppler-polarimetric microwave remote sensing of clouds and precipitation

This paper deals with mathematical modeling and simulation of echo-signals in both frequency and time domains. It establishes some important relationships between Doppler-polarimetric observables and weather object under observation.

Polarization signal components estimate in weather radar

New approach to use polarimetry for turbulence intensity estimate is proposed. It is based on estimation of the energetic characteristics of turbulent polarization spectrum. The proposed approach can be realized as a radar system that allows estimating the energetic characteristics of a set of polarization components of the received radar signal. The layout of a radar system for polarization components estimation is developed. Such approach can increase the informativity of weather radar systems relatively to obtaining information about factors that are the origin of changing polarization of reflected signal.

Copula ambiguity function for wideband random radar signals

In this paper we suggest the improvement and generalization of the wideband ambiguity function for radar signals. Sounding waveforms and reflected radar signals have different probability density functions, and this fact is not taken into account in classical definition of an ordinary ambiguity function. The proposed generalization of the ambiguity function is based on the copula notion and does not depend on a probability density function. The generalized copula ambiguity function is useful for both analysis/synthesis of sounding waveforms (auto-ambiguity) and reflected signal detection/measurement (cross-ambiguity). Application of this approach gets rid of a dependence on the signal probability distribution, implementing actually non-parametric approach with CFAR.

Ultrawideband Signal Processing Algorithms for Radars and Sodars

In this paper we use statistical approach to synthesize algorithms for digital signal processing in UWB noise radar and sodar. Parametrical and non-parametrical algorithms are synthesized and analyzed. Experimental check is done on the basis of developed acoustic physical model which is used to build a noise sodar prototype. Developed algorithms can be used in noise radars for different applications. The use of the UWB noise signal provides a very high resolution both in speed and range

Generalized copula ambiguity function application for radar signal processing

This paper presents a new approach to the definition of the radar ambiguity function. Using the notion of the copula a nonparametric extension of the wideband ambiguity function for random radar signals is suggested. This notion can be used for nonparametric signal detection and also for the radar signal analysis.

Through-the-wall surveillance technologies

This paper will present a brief overview of methods for solving the problem of surveillance behind the opaque wall. A low cost method for detecting moving objects behind the wall, based on the analysis of reflected pulse UWB signal is considered in more details. Demonstration of real work of the method is carried out with use of the operating breadboard model of the device implementing this method.

The approach to estimating critical wind speed in liquid precipitation using radar polarimetry

In this paper, forces and processes in the atmosphere that lead to drop deformation and vibration are considered. The expression that allows to define the reflected radar signal power redistribution between electromagnetic wave polarization components received with orthogonal antennas of Doppler-Polarimetric radar is given. It is shown that the drop fission into two parts takes place at the moment when additional drop surface tension equals zero. This is used to calculate the critical wind speeds for drops of corresponding sizes and use them when wind related phenomena estimate with polarization characteristics of radar signal.

Connection of reflected radar signal with liquid-hydrometeor deformation rate

In this paper forces and processes in the atmosphere that lead to drop deformation and vibration are considered. The expression that allows to define the reflected radar signal power redistribution between electromagnetic wave polarization components received with orthogonal antennas of Doppler-Polarimetric radar is obtained. The expression can be useful for creating turbulence intensity values scale when wind related phenomena estimate with polarization characteristics of radar signal.