Search academic texts

Information × Registration Number 0204U003179, 0101U002791 , R & D reports Title Physical, chemical and mineralogical properties of lunar surface from Clementine observation data, laboratory simulation and results of theoretical study of light scattering by regolith-like surfaces popup.stage_title Head Shkuratov Ju., Доктор фізико-математичних наук Registration Date 16-02-2004 Organization Kharkov National University named after V.N.Karazin popup.description2 A new method to detect the photometric anomalies of the lunar surface is applied to images obtained with UVVIS and NIR Clementine cameras. Also the laboratory and computer simulation is performed to develop such method.A strong negative anomaly of the lunar phase angle dependence of brightness at 10-600 was found at the Apollo-15 landing site. This anomaly shows disturbed structure of the lunar regolith related with jets of the lunar cabin. Besides, anomalies of the same types were found for fresh lunar craters. It was also shown that the anomalies could be due to seismic waves accompanied to the impact event. Some anomalies are associated with volcanic edifices. In this case the anomalies are due to pyroclastic deposits. The photometric peculiarity of the enigmatic Reiner-gamma region is confirmed.We present results from simultaneous photometric and polarimetric measurements of laboratory samples that simulate the structure of planetary regoliths. Computer modeling of shadow-hiding and coherent backscattering in regolith-like media are also presented. The laboratory studies were carried out with Kharkov Observatory's photometer/polarimeter at phase angles covering 0.2 - 17* and wavelengths of 0.63 and 0.45 *m.We studied a range of samples that characterize a variety of mechanical structures and albedo. A strong particle-size dependence of the negative branch of polarization for powdered dielectric surfaces was found.Our computer modeling shows that shadow-hiding affects the negative polarization only in combination with the coherent backscatter enhancement -- it decreases the amplitude of polarization. The computer simulation shows that scattering orders higher than second ones significantly contribute to negative polarization even in case of very dark surfaces.A new approach for remote sensing determination of the lunar surface composition is presented. The technique uses Clementine UVVIS data and results of spectral and chemical/mineral studies of lunar samples by the Lunar Soil Characterization Consortium. Distributions of the main rock-forming oxides (SiO2, FeO, TiO2, Al2O3), minerals (pyroxene, olivine, plagioclase, ilmenite), maturity degree (Is/FeO), and characteristic particle size are mapped with 1 km resolution. Our analysis shows that young crater regoliths are characterized with high content of pyroxene, coarser particles, and low degree of maturity. Product Description popup.authors popup.nrat_date 2020-04-02 Close