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Information × Registration Number 0207U004733, 0103U000665 , R & D reports Title Astrophysical research of the planets' surfaces and atmospheres according to the data of photometry and polarimetry popup.stage_title Head Korokhin Victor Valentinovich, Registration Date 14-08-2007 Organization Kharkov national university named after V.N. Karazin popup.description2 Objects of investigations are the lunar surface and Jovian atmosphere. Goal of the work is research of physical properties of planets atmospheres and surfaces. Methods of investigation are photometrical and polarimetrical, using theoretical analysis of data, theoretical and digital modeling the physical processes on planets surfaces and in atmospheres. New photopolarimetrical observations of the Moon at great phase angles (143° and 155°) (Kharkov) were carried out. These observations are continuation of the 2001-2003 years observations program. Absolute photometrical observations of the Moon with solar calibration have been carried out in four spectral bands at phase angles 45-120° using photoelectric method (Chuguev observational station of KhRIA of KhNU). Polarimetrical and photometrical observations of the Moon with high angular resolution in three spectral bands (red, green, blue) at phase angles 1.5-168° have been carried out on mountain Majdanak (Uzbekistan) during 2 month. Almost 1 terabytes ofdata have been collected. Data of lunar absolute photometry of 1986-87 years have been processed. Absolute values of reflectances of 73 lunar areas have been obtained. This data has a good agreement with Sytinskaya-Sharonov's photometrical system. A procedure of posteriori correction of the data of integral photometry of the Moon carried out by Lane and Irvine (1964-1965) and Rougier (1928) has been developed. This procedure allows one to decrease regular errors of integral phase curves related to the libration variations. On the base of corrected data it has shown that for relatively small phase angles (16°-43°), decreasing the phase slope with increasing the phase angle is observed. For middle and large phase angles (41°-120°), the phase slope is practically constant. It means that at relatively small phase angles phase dependence is formed substantially by micro-topography, at large phase angles the phase dependence is mainly formed by meso-topography. It was shown, that slope of integral lunar spectrum is changed nonmonotonicly with phase angle varying: there are minimum near 10° and maximum near 55°. For approximation of phase curves of average equigonal albedo in the range 6° Ј a Ј 120° we propose the following formula . Obtained results may be useful for testing the models of light scattering by lunar surface and for calibration of data of earth-based and space spectrophotometrical observations. New polarimetric observations of Jupiter (2004-2006), which continues observational program started in 1981, have been carried out. Observations of 2004 at filter "B" (leff =456 nm) give value of the north-south asymmetry of linear polarization degree 0.85±0.04%. The algorithm for building the maps of intensity and polarization for studying the thin structure of distribution of these parameters over jovian disk has been developed and realized. Studying of the Jupiter's polarization phase dependence shows that within observation accuracy there is no phase dependence at ? = 0??2? both at the central part of jovian disk and at the polar regions for blue and red spectral regions. That is why there is no need to carry out the Jupiter observations rigorously in opposition for studying the long-term variations of polarization at polar regions. On the basis of new observational data (2000-2004), of reprocessed old data (1981-1998), and of the data of other observers (1968, 1972-74) the anticorrelation between asymmetry of polarization and insolation has been found. The mechanism of influence of seasonal variations of insolation on north-south asymmetry of polarization formation has been proposed. Most likely the Jupiter's polar stratospheric haze consists of solid particles of polyaromatic hydrocarbons (naphthalene and phenantrene). It was shown that homogeneous nucleation is the principal mechanism of formation of such aerosols. Possible effect of irregular factors (solar cosmic rays) on polarization is also noted. A model for describing the observed phase dependences of brightness and linear polarization degree of the lunarsurface has been developed. It takes into account both light scattering on regolith microparticles, which have complex structure, and effects, which appear in macroscale at light scattering by rough surface. An algorithm for light scattering calculations using Monte-Carlo method in multi-component rarefied medium has been developed and realized using C# programming language. The program was passed all tests successfully. Оn the basis of this program development of the models of light scattering by Jupiter's stratospheric aerosol haze and by cloud layers have been started. Fully new version of program complex xIRIS for .NET has been developed. Studying the correlation links between spectral characteristics of lunar soil and chemical and mineralogical composition using the LSCC data is started. Multiple linear regression and artificial neural networks were used for this. Conclusion about availability of artificial neural networks for prediction of chemical and mineralogical composition using spectroscopy has been made. Algorithm and software on the basis of artificial neural networks (ANN) have been developed for prognosis of chemical and mineralogical composition of lunar soil using LSCC data and "Clementine" spacecraft UVVIS maps. The algorithm realizes a nonlinear prognosis method with taking into account morphological classification of surface. Using this algorithm, new map of TiO2 distribution over the lunar disk has been constructed. This map is the most reliable now. Proposed method could be a useful for the strategy in analysis of lunar data obtained with spacecrafts especially for the Chandrayaan-1 mission. It is drawn a conclusion that the ANNs are powerful technique for analysis of astronomical data: using the ANNs allows us to study empirical links between spectral characteristics of lunar soil and composition parameters without any restrictions on the character of these relations, and make zoning of surfaces on the base of any quantity of parameters. Relational database of PPR from Galileo spacecraftand utilities for comfortable and efficient work with it have been developed. We plan to use the database for testing the models of light scattering by various formations in Jovian atmosphere. Implementation of the formulas of perspective cartographic projection for space bodies of arbitrary shape as a .NET class library for xIRIS has been realized. Product Description popup.authors popup.nrat_date 2020-04-02 Close