月球内部结构磁成像技术

发布时间：2018-02-09 15:10

本文关键词： 偏心球模型磁强计阵列球体电磁感应理论 Laplace逆变换数值算法　出处：《中国科学院国家空间科学中心》2016年硕士论文　论文类型：学位论文

【摘要】：作为地球唯一的天然卫星,月球是人类探索宇宙迈出第一步的落脚点。月球不具有与地球类似的全球性内禀偶极磁场,无法形成大尺度磁层结构,且其半径和内部电导率(尤其是月壳电导率)远低于地球;当变化的行星际磁场掠过月球时,会在极短的时间内完全穿透月球。这种特性为研究行星际磁场与月球的相互作用提供了非常好的手段。月球深部磁成像技术是我们提出的一种新的月球内部结构探测方法。它以地磁测深理论为基础,在月球表面进行高精度磁场矢量探测,特别是由行星际磁场跃变所产生的月球感应磁场三分量变化,进而反演月球深部的地质结构。这将有助于人们认知月球壳层电导率的分布特征,也有助于认知月壳的内部结构与非对称性等特征。1969年,美国的Apollo 12和Explorer 35磁强计分别在月面和月球轨道上同时对数十个行星际阶跃磁场的扰动事件进行了观测,并记录了磁场三分量的变化;随后Apollo 14、15、16及前苏联的Lunokhod 2磁强计也分别在月表不同位置对固有磁场进行了单点探测,并推断出了月球内部的一维结构分布。我国未来的探测可以在此基础上更进一步——在月表设置一个或多个磁强计阵列,并通过磁场联测的数据反演出各测点垂向厚度的差异和更高精度的月球内部结构。月球车和它携带的各种仪器可以提供技术支持,宇航员可通过实际操作完成这些科学实验。受到月球空间特殊电磁环境的影响和限制,在月表布设的测区面积不会太大,测点间距可能只相当于月球半径的几百分之一甚至几千分之一,这使得测区的曲率几乎可以忽略不计。为保证数据的高质量和可靠性,对磁强计阵列位置的选取就非常重要。本研究针对均匀模型,利用球体电磁感应理论,计算了不同的模型参数下,行星际阶跃磁场在月表产生的感应磁场,并选取部分测点给出了其变化过程;对于二维偏心模型,还给出了相邻测点的磁场分量差值与垂向壳层厚度差值、测点间距的定量关系,希望能够对将来的磁强计阵列布置方案起到一定的参考作用。
[Abstract]:As the only natural satellite of the earth, the moon is the first step in the exploration of the universe. The moon does not have a global intrinsic dipole magnetic field similar to that of the earth, and is unable to form a large-scale magnetospheric structure. And its radius and internal conductivity (especially the conductivity of the lunar shell) are much lower than those of the Earth; when the changing interplanetary magnetic field skims over the moon, It will penetrate the moon completely in a very short time. This characteristic provides a very good means to study the interaction between interplanetary magnetic field and moon. The deep magnetic imaging technology of the moon is a new interior structure of the moon proposed by us. Methods of detection. It is based on geomagnetic sounding theory, High precision magnetic field vector detection on the lunar surface, especially the three-component variation of the lunar induced magnetic field caused by the interplanetary magnetic field jump, This will help people to understand the distribution characteristics of the conductivity of the lunar crust, as well as the characteristics of the inner structure and asymmetry of the lunar crust. In 1969, The Apollo 12 and Explorer 35 magnetometers in the United States have simultaneously observed the disturbance events of the interplanetary step magnetic field on the lunar surface and the lunar orbit, respectively, and recorded the variation of the three components of the magnetic field. Subsequently, the natural magnetic field was detected at different positions on the lunar surface by the Apollo 14, 15 and 16 magnetometers and the Lunokhod 2 magnetometer of the former Soviet Union, respectively. The one-dimensional structure distribution of the lunar interior has been inferred. The future exploration in China can build on this by placing one or more magnetometer arrays on the lunar table. The difference in vertical thickness of the measured points and the higher accuracy of the lunar interior structure. The lunar rover and the various instruments it carries can provide technical support. Astronauts can perform these scientific experiments through practical operation. Affected and restricted by the special electromagnetic environment of the lunar space, the area of the survey area laid on the lunar surface will not be too large. The distance between the measured points may be 1% or even several thousand parts of the radius of the moon, which makes the curvature of the measured area almost negligible. In order to ensure the high quality and reliability of the data, It is very important to select the position of magnetometer array. In this study, the inductive magnetic field of interplanetary step magnetic field on the moon surface is calculated by using the spherical electromagnetic induction theory in accordance with the uniform model. For the two-dimensional eccentric model, the quantitative relationship between the magnetic field component difference of adjacent measuring points and the thickness of vertical shell and the distance between measuring points is given. It is hoped that it will play a certain reference role in the future magnetometer array arrangement.
【学位授予单位】：中国科学院国家空间科学中心
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P184

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