Retrieval Of Lunar Albedo Based On The Hapke Model

Lunar albedo is an important optical parameter of Lunar radiation, reactionenergy balance of climatological tables, and also a significant parameter used fordistinguishing the retrieval content and classification of lunar mineral, which laysbasic foundation for lunar calibration and resources development and expand ourunderstanding of the origin, history, formation and elevation of the Moon.After summarizing albedo retrieval models, there are three methods of Hapkemodel, including kernel driven BRDF model and statistical model. More extensiveapplication of the Hapke model and statistical model for the inversion of lunar surfacefeatures of regional albedo are selected, by comparing the advantages, disadvantagesand applicability of the three methods. The statistical model is the ratio of thereflection energy to total incident energy. Hapke models are the approximateanalytical solutions to the equation of radiative transfer, which reflects the opticalproperties of surface, including roughness and surface composition of mineralcomposition, particle shape porosity and surface. According to the observedreflectivity of satellite imagery, a series of different expressions are deduced, coveringthere are bidirectional reflectance, bidirectional reflection coefficient and bidirectionalreflective factor. The formula of inversion albedo is derived by the basic expression ofthe Hapke mode.There exists ups and downs in the lunar terrain, which has a certain impact onremote sensing data. In the Hapke model, the influence of the roughness of the macroroughness on the roughness is considered, and the influence of the slope gradient, theaspect ratio and the surrounding terrain on the albedo is also considered. Based onSandmeier terrain correction model, analysis of the parameters of the model, themacro topography influence function is obtained considering the incident solarirradiance and entrance pupil radiance. According to the solar spectrum and two basicterrain factors like slope aspect, the following parameters of the model are taken into consideration, including the incident angle and emergence angle on a slope surface,the terrain configuration factor, the solar direct irradiance and the total irradiance on ahorizontal surface, the binary coefficient indicating whether the pixel is sunlit. As thecorrection method, the model has been applied to part region of lunar mare and lunarcrater in Tycho and the lunar albedo is retrieved. Therefore, the Hapke modelconsidering the terrain influence is established.Using the M3data obtained by Chandrayaan-1satallite is chosen, Hapke modeland statistical model are used for retrieving of lunar albedo on narrow band, throughwhich surface albedo of wide band surface are then obtained. The empirical formulatransferring albedo of narrow band to wide band is applied, which uses a largenumber of data to simulate and establish linear regression. The visible wavelength ofhigh spectral data M3in the single band is also used for linear regression, which uesesa single band of pupil radiance and solar irradiance incident is the ratio of theproportional coefficient in linear simulation. The inversion results of two methods areanalyzed and compared. The results were compared with the early and the observer oflunar surface in typical areas of application of observation instrument. The accuracyof the inversion results is analyzed, and the inversion albedo of the Hapke modelconsidering the terrain effect is more accurate.