Yazhou Yang, Te Jiang, Hao Zhang, Yang Liu, Yongliao Zou
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引用次数: 0
Abstract
In photometric modeling, disk function plays a crucial role in describing scattering behaviors related to the local incidence and emission angles of an observed surface. Finding a proper disk function is important for normalizing spectra observed under different observing geometries. This study evaluates the performances of five different disk functions, including the Lommel-Seeliger function, and functions proposed by Minnaert, McEwen, and Akimov, using bidirectional reflectance distribution function (BRDF) data of lunar-type minerals and Apollo lunar soils. BRDF measurements of olivine, orthopyroxene, plagioclase, and ilmenite were conducted to examine the effects of mineralogy and particle size. Our results indicate that the Akimov empirical function is most effective in reducing discrepancies among data measured under varied incidence and emission angles for both pure minerals and lunar soil samples. Two empirical functions for the free parameter q in this model were generalized based on pure mineral data, but are unsuitable for lunar soil samples. The q derived for six Apollo lunar soil samples are much lower than those for pure silicate minerals but align well with remote sensing observations, with no distinct differences between lunar mare and highland soil samples, possibly due to extensive space weathering on the lunar surface. The q values at a phase angle of 70° show the strongest correlation with the widely used maturity index Is/FeO, and two empirical functions between Is/FeO and q(70°) for bands 550 and 750 nm were established, which may be used to quantify the degree of space weathering.
期刊介绍:
The Journal of Geophysical Research Planets is dedicated to the publication of new and original research in the broad field of planetary science. Manuscripts concerning planetary geology, geophysics, geochemistry, atmospheres, and dynamics are appropriate for the journal when they increase knowledge about the processes that affect Solar System objects. Manuscripts concerning other planetary systems, exoplanets or Earth are welcome when presented in a comparative planetology perspective. Studies in the field of astrobiology will be considered when they have immediate consequences for the interpretation of planetary data. JGR: Planets does not publish manuscripts that deal with future missions and instrumentation, nor those that are primarily of an engineering interest. Instrument, calibration or data processing papers may be appropriate for the journal, but only when accompanied by scientific analysis and interpretation that increases understanding of the studied object. A manuscript that describes a new method or technique would be acceptable for JGR: Planets if it contained new and relevant scientific results obtained using the method. Review articles are generally not appropriate for JGR: Planets, but they may be considered if they form an integral part of a special issue.