报告题目：Disk-Resolved Photometric Analysis and Applications on Dawn Vesta Data

　　报告人：Jian-Yang Li 博士 Planetary Science Institute

　　报告摘要：The reflectance of particulate surfaces of planetary objects is determined by the physical properties and packing status of their regolith. Therefore, understanding the characteristics of reflectance with respect to illumination and viewing geometry provides a method to infer the properties of planetary surfaces. In addition, photometry techniques also allow us to correct the imaging and spectroscopic data acquired at various geometric conditions to a common geometry, enabling the mapping of planetary surfaces and direct comparisons with laboratory measurements for mineralogical interpretations. The ability to predict the brightness of a planetary surface at arbitrary geometry makes photometry critical for essentially all planetary exploration missions. Dawn spacecraft orbited asteroid (4) Vesta from spring 2011 to fall 2012, collected a large amount of multi-color imaging data through its Framing Camera (FC). The imaging data collected during the Approach and the first orbit phase, Survey Orbit (SO), cover >80% of the surface at a range of phase angles from ~7o to 110o, making an excellent set of data for a detailed photometric study of Vesta. I will introduce the techniques for disk-resolved photometric analysis for planetary surfaces in general, describe the commonly used photometric models, the applications of photometric modeling on Dawn Vesta data, and discuss the results and their implications on the physical properties of Vesta. Vesta’s surface shows a large range of variations in albedo, dominated by the mixing of bright materials of endogenic origin and dark materials of exogenic origin. The albedo and color mosaics of Vesta reveal a highly heterogeneous surface, resulted from a complex collisional, geological, and regolith evolution history of Vesta.

　　报告时间：2017年6月27日 周二 15:00

　　报告地点：（北京西路2号）紫台大楼419房间

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