基于场理论的“嫦娥4号”着陆区亮温时空分布特征研究

“嫦娥4号”（Chang’e-4）将首次实现在月球背面软着陆，而着陆区初步定为月球背面南极–艾肯（South Pole-Aitken，SPA）盆地内的冯·卡门（Von Kármán）撞击坑。利用“嫦娥”微波辐射计穿透性强的特点，针对微波辐射亮温缺乏场分析的问题，从场观点出发利用SVD方法分析冯·卡门撞击坑的亮温时空分布特征。结果表明冯·卡门撞击坑的3 GHz昼夜亮温场和37 GHz昼夜亮温场之间存在显著的耦合模态，同时在撞击坑内的亮温变化趋势相对一致；FeO+TiO₂（FTA）含量高的区域其相关性较高，也是亮温变化的关键区域，但是其等值线密度和FTA含量没有明显相关关系，主要和月表粗糙度相关。最后通过分析冯·卡门撞击坑的亮温时空分布特征综合地形特征、地层单元和物质化学成分等因素，为Chang’e-4着陆区的选择提供了参考。

The Research of Temporal and Spatial Distribution of Microwave Brightness Temperature in Chang'E-4 Landing Area Based on Field Theory

Chang''e-4 (CE-4) probe will achieve the first soft landing on the farside of the moon in the history of mankind, and the landing zone is tentatively fixed in the Von Karman impact crater which is in the South Pole-Aitken basin. In view of the lack of field analysis of microwave radiation brightness temperature, analyzed the brightness temperature''s temporal and spatial distribution characteristics of Von Karman impact crater was analyzed based on the field and the penetrability of Chang''e Microwave radiometer. The results show that there is a significant couple mode between 3GHz diurnal brightness temperature field and 37GHz diurnal brightness temperature field,,and the trend of brightness temperature appeared consistent in the crater. It also turns out that the area with high FeO+TiO₂ (FTA) content has a higher relativity, which is the key area of brightness temperature change. Nevertheless, the FTA content does not have significant impact on the density of contours. Contrarily, the density of contours is mainly influenced by the roughness of the moon''s surface. Finally, the research provided a reference for the choice of landing zone of CE-4 probe by analyzing the temporal and spatial distribution characteristics of brightness temperature, stratigraphic unit, chemical constituents of substance and other factors in Von Karman impact crater.