应用重力场模型GL1500E和LLR天平动参数估算月核大小及其组成  

Estimation of the Size and Composition of the Lunar Core Based on the Gravity Field Model GL1500E and LLR Physical Libration Parameters

作　　者：钟振[1,2,3] 张腾 段炼 李毅 朱化强 ZHONG Zhen;ZHANG Teng;DUAN Lian;LI Yi;ZHU Huaqiang(School of Physics and Electronic Science,Guizhou Normal University,Guiyang 550001,China;School of Natural Resources and Surveying,Nanning Normal University,Nanning 530001,China;Key Laboratory of Environment Change and Resources Use in Beibu Gulf,Ministry of Education,Nanning Normal University,Nanning 530001,China)

机构地区：[1]贵州师范大学物理与电子科学学院,贵州贵阳550001 [2]南宁师范大学自然资源与测绘学院,广西南宁530001 [3]南宁师范大学北部湾环境演变与资源利用教育部重点实验室,广西南宁530001

出　　处：《武汉大学学报（信息科学版）》2021年第2期238-243,共6页Geomatics and Information Science of Wuhan University

基　　金：国家自然科学基金(41864001);武汉大学测绘遥感信息工程国家重点实验室开放基金(17P03);贵州省科技计划项目(黔科合平台人才[2018]5769);北部湾环境演变与资源利用教育部重点实验室开放基金(2015K03)。

摘　　要：针对月核大小及密度估计问题,利用高分辨率重力场模型GL1500E的二阶位系数和LLR(lunar laser ranging)天平动参数,考虑月核分层为外核和内核的情况,结合非线性粒子群优化算法,对月核大小和组成进行了估计。大批量的统计结果表明,大概率分布的外核半径rc1约为469 km,内核半径rc2约为303 km,外核密度ρc1约为4613 kg/m3,内核密度ρc2约为7004 kg/m3,月幔密度ρm约为3340 kg/m3。月幔密度非常接近地质研究结果3360 kg/m3,内外核半径与近期其他研究结果相近,估算的月核大小与密度组成具有一定的参考价值。若月核由纯铁和硫化亚铁组成,则研究表明,内核大部分由纯铁组成,外核大部分由硫化亚铁组成。The lunar core is stratified into an outer core and an inner core. They can be estimated according to the second degree of gravity field model and selenophysical libration parameters from lunar laser ranging(LLR). We use the high-resolution lunar gravity field model GL1500 E to evaluate the size and density of lunar core, which are inversed through a nonlinear particle swarm optimization. A large number of inversion indicates that, the outer diameter of the outer core is about 469 km with a corresponding density of 4 613 kg/m~3, the radius of the inner core is around 303 km with a corresponding density of 7 004 kg/m~3 and the density of mantle surrounds 3 340 kg/m~3, which is quite close to the geological value of 3 360 kg/m~3. The radii of inner core and outer core are quite close to other recent studies as well. The size and density of the lunar core found here can be therefore meaningful. If the lunar core is composed of pure iron and ferrous sulfide, our study shows that the inner core is mainly composed of pure iron whereas the outer core is largely composed of ferrous sulfide.

关 键 词：重力场模型 天平动参数 粒子群优化算法 月核大小 月核组成 

分 类 号：P223[天文地球—大地测量学与测量工程]