基于LOLA数据的月球光照模型及应用研究

发布时间：2018-07-23 16:55

【摘要】：月面光照是月球表面演化研究的重要因素之一,影响月球表面的温度分布,是未来人类月面活动的主要能量来源,也是决定未来月面构建科研基地位置选择的重要因素之一。太阳辐射是影响月表空间风化的重要因素之一,月壤颗粒在经受长期的空间风化作用后会在微观结构上产生变化,形成月壤的独特性质。对月遥感探测热发射谱图的解译、研究月球热演化模型同样需要月表太阳辐射作为重要的分析因素。因此,构建全月光照特性分析模型,研究全月和局部地区的光照特性,是一项非常重要的工作。目前,月球光照特性的研究主要位于月球两极,缺乏月球中低纬度乃至全月光照特性的研究,月球热演化研究也缺乏相应的光照信息参考,构建高分辨率全月光照信息数据库是月球科学研究中亟待解决的问题之一。针对月面光照特性研究不足的问题,本文所做的主要工作如下:1.构建了不考虑地形的理想情况下的几何光照模型。计算结果表明,在某一光照时刻,太阳高度角由直射点向两极环状递减,均存在南北两极完全被照射的时刻;长期时间范围内,全月光照率在50%-58%之间,正面光照时长多于月球背面,高纬度地区光照率高于中低纬度地区,在纬度88.5°附近最大,光照率变化周期约为19年。2.在现有的两极光照模型基础上进行改进,建立了适用于全月的光照模型。基于LOLA地形数据创建了一年的全月光照数据库。结果表明,两极是光照率变化最大的地区,一年内最大光照率为91.69%,存在永久阴影区。月球正面的月海是中低纬度光照条件较好的地区,而两极地区地势较高的山脊处拥有良好的光照条件。3.利用改进的模型,在充分考虑进动周期的影响下,对月球极区和中低纬度的光照特性进行研究。结果表明:(1)月球两极均不存在永久光照区,存在永久阴影区,首次给出半个进动周期的极区光照分布。在一个进动周期内,南北两极的永久阴影区面积分别为7215km2和1683km2,最优点的光照率分别为91.46%和90.98%,最长连续阴影时间分别为4.2天和5.0天,最长持续光照时间分别为231.0天和203.9天。相比之前研究结果,北极地区的最大光照率提高1.41%,南极地区的永久阴影区面积提高854km2。(2)以Aristarchus高原为代表,对中低纬度地区的光照特性进行详细研究,对选取典型地貌点的光照变化做了分析。简要阐述了Tycho撞击坑、东海、Marius Hills地区、雨海和莫斯科海的光照条件,并为着陆区和月球演化研究位置的选择提供了建议。本文的研究得到了全月范围内高空间分辨率下的光照率分布,这不仅可以作为今后探月计划着陆点选择、科学目标制定以及工程设计的依据,也为未来月球热演化研究提供了光照数据参考。
[Abstract]:Lunar surface illumination is one of the important factors in the research of lunar surface evolution. The temperature distribution of the lunar surface is the main energy source of the future human lunar surface activity, and it is also one of the important factors to decide the location of the future lunar surface construction research base. Solar radiation is one of the important factors that affect the spatial weathering of lunar surface. After long-term spatial weathering, lunar soil particles will change in microstructure and form the unique properties of lunar soil. For the interpretation of the thermal emission spectrum of lunar remote sensing exploration, the study of lunar thermal evolution model also needs the solar radiation of the lunar surface as an important analytical factor. Therefore, it is very important to construct an analytical model of the characteristics of full moon illumination and study the illumination characteristics of the whole moon and local areas. At present, the study of lunar illumination is mainly located at the polar pole of the moon, lacking the study of the moon's mid-latitude and even full-moon illumination characteristics, and the study of the lunar thermal evolution is also lack of the corresponding illumination information reference. It is one of the problems to be solved urgently in lunar scientific research to construct high-resolution full-moon light information database. The main work of this paper is as follows: 1. A geometric illumination model without considering terrain is constructed. The calculated results show that at a certain time of illumination, the solar height angle decreases from the direct point to the polar circle, and there is a time when the north and south poles are completely illuminated, and in the long time range, the total moonlight illumination ratio is between 50% and 58%. The duration of positive illumination is longer than that of moon backside, and the illumination rate in high latitude is higher than that in middle and low latitude, and it is the largest at latitude 88.5 掳, and the period of illumination rate variation is about 19 years. Based on the existing two-pole illumination model, the illumination model for the whole moon is established. Based on LOLA topographic data, a full-moon-based database is created for one year. The results show that the maximum illumination rate in one year is 91.69 and there is a permanent shadow region. The lunar sea on the front of the moon is an area with better illumination conditions at the middle and low latitudes, while the ridge with a higher topography in the polar region has a good illumination condition. Based on the improved model, the illumination characteristics of the lunar polar region and the middle and low latitudes are studied with the full consideration of the precession period. The results show that: (1) there is no permanent illumination region at the two poles of the moon, and there is a permanent shadow region. For the first time, the illumination distribution in the polar region of the half-precession period is given. In a precession period, the area of permanent shadow area at the north and south poles is 7215km2 and 1683km2, respectively. The optimum illumination rate is 91.46% and 90.98%, respectively. The longest continuous shadow time is 4.2 days and 5.0 days, and the longest continuous illumination time is 231.0 days and 203.9 days, respectively. Compared with previous studies, the maximum illumination rate in the Arctic region is increased by 1.41%, and the area of the permanent shadow area in the Antarctic region is increased by 854 km2. (2) the illumination characteristics of the middle and low latitudes are studied in detail, as represented by the Aristarchus Plateau. The illumination variation of typical landforms is analyzed. The illumination conditions of the Tycho impact crater, the Marius Hills area of the East China Sea, the Rain Sea and the Moscow Sea are briefly described, and suggestions are provided for the selection of the landing area and the location of the lunar evolution. In this paper, the distribution of illumination rate at high spatial resolution in the whole moon range is obtained, which can not only be used as the basis for the selection of landing sites for the lunar exploration plan, the formulation of scientific targets and the engineering design in the future. It also provides a reference for the future study of lunar thermal evolution.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P184.5

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