Adaptive Algorithms for Radar Detection of Turbulent Zones in Clouds and PrecipitationThe

Abstract-We analyze the statistical properties of normal galaxies to be detected in the all-sky survey by the eROSITA X-ray telescope of the Spectrum-X-Gamma observatory. With the current configuration and parameters of the eROSITA telescope, the sensitivity of a 4-year-long all-sky survey will be ≈10 −14 erg s −1 in the 0.5-2 keV band. This will allow ∼(1.5-2) × 10 4 normal galaxies with approximately the same contribution of star-forming and elliptical galaxies to be detected. All galaxies of the X-ray survey are expected to enter into the existing far-infrared (IRAS) or near-infrared (2MASS) catalogs; the sample of star-forming galaxies will be approximately equivalent in sensitivity to the sample of star-forming galaxies in the IRAS catalog of infrared sources. Thus, a large homogeneous sample of normal galaxies with measured X-ray, near-infrared, and far-infrared fluxes will be formed. About 90% of the galaxies in the survey are located within ∼200-400 Mpc. A typical (most probable) galaxy will have a luminosity log L X ∼ 40.5-41.0, will be located at a distance of ∼70-90 Mpc, and will be either a star-forming galaxy with a star formation rate of ∼20M yr −1 whose X-ray emission is produced by ultraluminous X-ray sources (ULXs) or an elliptical galaxy with a mass log M * ∼ 11.3 emitting through to a hot interstellar gas. The galaxies within 35 Mpc will collectively contain ∼102 ULXs with luminosities log L X > 40, ∼80% of which will be the only luminous source in the galaxy. Thus, although the angular resolution of the eROSITA telescope is too low for the luminosity function of compact sources in galaxies to be studied in detail, the survey data will allow one to investigate its bright end and, possibly, to impose constraints on the maximum luminosity of ULXs.PACS numbers : 98.70.Qy

In many cases one can faced with situation of unknown and unstable statistical models of signals and interferences. It is known that markovian processes give good chance for simulation of random processes with non-Gaussian distribution. In this paper the basic approaches to synthesis of signal detection algorithms are considered under the conditions of parametrical aprioristic uncertainty of both signal and interference situations.

This paper deals with the algorithm for estimating the turbulence intensity in rain, which is developed on the basis of the model of Doppler-polarimetric spectra of radar signals, reflected from turbulent zones in precipitation. The relationship between Doppler spectrum width of rain and eddy dissipation rate is established at two orthogonal polarizations. The approximation of this relationship by Weibull model provides mathematical convenience for further analysis and synthesis. Algorithm for the estimation of turbulence intensity is developed on the basis of modeled and measured Doppler-polarimetric data. This algorithm is researched by statistical simulation. It is shown that Doppler-polarimetric approach provides accuracy increase in comparison with Doppler method without polarization information.

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This work addresses the problem of stochastic modelling of short time series. Questions of autoregressive spectral analysis and Autoregressive Moving Average spectral analysis and its application in the tasks of signal processing of informational measuring systems are considered. Autoregressive and Autoregressive Moving Average spectral methods as well as by Discrete Fourier Transform are given