Wave scattering from self-affine surfaces

Electromagnetic wave scattering from a perfectly reflecting self-affine surface is considered. Within the framework of the Kirchhoff approximation, we show that the scattering cross section can be exactly written as a function of the scattering angle via a centered symmetric Levy distribution for general roughness amplitude, Hurst exponent and wavelength of the incident wave. The amplitude of the specular peak, its width and its position are discussed as well as the power law decrease (with scattering angle) of the scattering cross section.Comment: RevTeX, 4 pages including 2 figures. Submitted Phys. Rev. Let

National monetary system of the Republic of Belarus: exchange rate policy

The article is devoted to the monetary system of the Republic of Belarus. Presents the dynamics of average official rate of the Belarusian ruble against foreign currencies. During the analysis it was found that the average official exchange rate of the Belarusian ruble against the dollar, Euro and Russian ruble fluctuates constantly, therefore in the Republic of Belarus faces the challenge of achieving stability in the exchange rate of the Belarusian ruble. To improve the national monetary system must, above all, the increase in international reserves (foreign exchange reserves), as the higher the volume of gold reserves, the more stable and reliable economic situation of the country.Статья посвящена валютной системе Республики Беларусь. Представлена динамика среднего официального курса белорусского рубля по отношению к иностранным валютам. В ходе анализа было установлено, что средний официальный курс белорусского рубля по отношению к доллару, евро и российскому рублю постоянно колеблется, поэтому в Республике Беларусь стоит задача достижения стабильности обменного курса белорусского рубля. Для улучшения национальной валютной системы необходимо, прежде всего, увеличение ЗВР (золотовалютных резервов), так как, чем выше объем ЗВР, тем стабильнее и надежнее экономическое положение страны

GNSS reflectometry for earth remote sensing

Reflectometry is one of many new applications made possible by freely available global navigation satellite system (GNSS) signals. Reflectometry measurement geometry has some features that are significantly different from conventional radar or radiometry. To understand the potential utility of GNSS reflectometry (GNSS‐R), first this chapter reviews some of the broader principles of remote sensing and their application to Earth observation. Following a brief history of the field, it describes the fundamental principles and basic observables used in GNSS‐R. This is followed by applicable scattering models and their numerical evaluation. Before developing a comprehensive electromagnetic model for the Delay‐Doppler map (DDM), the chapter explores the basic geometry of bistatic radar, showing the relationship between the DDM and surface coordinates. This is used to define the essential features of the DDM which can be used to extract information about the roughness and reflectivity of the surface