月基极紫外图像重构磁赤道面等离子层顶

Plasmapause position is one of the most important parameters in inner magnetosphere researches. The minimum L algorithm and the genetic algorithm have been successfully applied to the inversion of the moon-based plasmaspheric extreme ultraviolet images. Based on the two algorithms, plasmaspheric ion density distributions and magnetic equatorial plane plasmapause positions can be relatively accurately obtained from moon-based extreme ultraviolet images modeled at specific lunar positions. In this project, the dynamic plasmaspheric model will be used to study the properties of the moon-based plasmaspheric extreme ultraviolet images under different interplanet and geomagnetic conditions at different positions of lunar orbit, and to obtain the distribution properties of the shadows by the main part of the plasmasphere and the Earth for the first time. Then the minimum L algorithm will be improved accordingly to ensure that the magnetic equatorial plane plasmapause positions can be reconstructed from the moon-based images obtained at any position of the lunar orbit and to provide important basis for the researches of plasmapause evolution and fast and accurate inversion of the plasmaspheric ion densities.

等离子体层顶位置是内磁层研究中最重要的参数之一。最小Ｌ算法和遗传算法已被成功应用于月基地球等离子体层极紫外图像的反演中，应用该算法可以较准确地从特定位置模拟的月基极紫外图像获得等离子体层离子密度分布和磁赤道面等离子体层顶位置。本项目将采用动态等离子体层模型深入研究不同行星际/地磁活动条件下、不同月球轨道位置处的月基等离子体层极紫外图像，首次获得月基极紫外图像中等离子体层主体遮挡和地球遮挡的分布特征，对最小L算法进行改进，从而能从月球轨道上任何位置准确重构出磁赤道面等离子体层顶位置，为研究等离子体层顶演化特性和准确、快速反演等离子体层离子密度分布奠定重要基础。

等离子体层顶位置是内磁层研究中的最重要参数之一。基于我国嫦娥三号月基极紫外相机对地球等离子体层的成像观测，本项目开展了地球等离子体层模拟研究、嫦娥三号极紫外相机数据的反演研究。首先采用动态地球等离子体层模式深入研究了不同太阳风和地磁活动条件下、不同月球轨道位置处的月基等离子体层极紫外图像特性。其次，根据嫦娥三号极紫外相机数据分析需要，采用三维混合模拟程序模拟了磁鞘极紫外辐射特性，消除磁鞘极紫外辐射对图像反演的影响。再次，采用最小L算法对嫦娥三号的实际观测数据进行了成功的反演，得到了磁赤道面等离子体层顶位置分布，并与等离子体层就位探测结果进行了比较，证明了反演方法的正确性和反演结果的准确性。本项目已按计划完成了项目申请书中的所列的所有研究内容，研究结果为地球等离子体层的后续探测和研究奠定了重要基础。