模拟月球浅表层雷达波传输机理研究

Some microwave instruments have been onboard new lunar satellites, and the moon ground penetration radar will be employed on our Chang'e-3 rover. However, it is not clear to explain some lunar radar measurements for geological application. In the proposal, based on some typical lunar rockfacies and occurances and their electrical parameters, some samples with similar rockfacies and occurances of igneous rocks on the earth are collected. And some lunar regolith and rock groups with different rockfacies and occurances are built by employing effective media model. Thus, the differences and gradient of change on the depth of their electrical parameters can be evaluated. By the simulated layered lunar regolith and rocks with rough surfaces, the mechanism of radar transfer will be studied. The equation of radar transfer can be built, including its absorbing boundary conditions and numerical solution. The results will be tested an validated by ground penetration radar (GPR) in the laboratory and field. Some luanr satellite radar data will be processed and analyzed. And lunar subsurface electrical parameters and depth will be derived. Thus, some typical radar echos can be explained for their geological application. And the water-ice in the lunar polar regolith will be re-evaluated and the high circular polaration ratios by lunar surface rough will be re-analyzed. It will be significant for the process and analysis of our moon ground penetration radar onboard the Chang'e-3 rover.

新近月球卫星都搭载微波探测器，我国Chang'e-3卫星也将搭载探月雷达。但是，已知月球雷达测量结果的地质解释目前还不明确。该申请拟根据月表典型岩性的岩相和产状，以及已知电性参数，通过地面火成岩类似岩相和产状的样品采集，利用等效介质模型，模拟月表典型月壤月岩组合，研究不同岩相和产状月壤月岩组合的电性参数差异及其深度上的变化梯度。由此，开展具有粗糙界面的多层月壤月岩介质中极化雷达波传输机理研究，建立多层月壤月岩介质中极化雷达波传播方程，研究其边界条件和数值解法，并分别通过试验室和野外探地雷达试验验证。最后，应用于月球典型地区雷达数据处理分析，实现月球浅表层下界面电性参数和深度反演，从而重新认识月球卫星和月面测量的特殊雷达回波特性的地质含义和月球浅表层结构特征，重新区分和评价极地永久阴影区含水冰月壤和月面粗糙度引起的强雷达回波园极化比值，也将为我国Chang'e-3探月雷达数据处理提供科学依据

新近月球卫星都搭载微波探测器，特别地我国Chang'e-3卫星“玉兔号”月球车也成功搭载探月雷达开展了月球浅表层探测。通过该项目，分别基于Maxwell-Garnett理论和Bruggeman理论，耦合固体颗粒粒径大小和孔隙度的关系，建立了月壤等效介质模型。结合地面火山岩不同岩相和产状，采集不同火山岩样品，通过物性及化学成分测试，分析其与阿波罗时期真实样品之间的相关性，模拟典型月壤样品，并利用矢量网络分析仪测量模拟月壤和单一矿物介电常数，验证模型。同时，以模拟的典型月壤月岩组合为等效介质，数值模拟分析了多层月壤月岩介质中极化雷达波传播过程及其影响因素，建立了多层月壤月岩介质中极化雷达波传播方程，并分别开展了试验室和野外探地雷达探测试验，提取了火山岩区不同期次火山岩的接触关系。由此，在利用月球卫星搭载雷达遥感数据Mini-RF预处理基础上，通过不同模型反演了月表介电常数，分析了月表撞击坑溅射物和火山碎屑岩在Mini-RF图像的不同散射特性。特别围绕Chang'e-3卫星探月雷达数据应用，基于随机等效介质理论和FDTD模型，模拟计算得到月球三层随机介质正演模型和探月雷达电磁响应模拟数据，结合有限带宽阻抗(BLIMP)反演理论，利用有限带宽阻抗(BLIMP)反演方法，基于Chang'e-3探月雷达数据，提取验证了月球浅表层三层分层结构，率先成功反演月球浅表层三层的介电常数，进一步深刻认识了月球浅表层的结构。基于反演的月球浅表层介电常数和等效介质模型，进而反演得到了月表浅层矿物组成，并通过Apollo月岩样品和其它探测结果的验证，为进一步认识月球浅表层结构的形成演化研究提供依据。依托该项目，发表了16篇论文，其中5篇SCI检索，11篇EI检索。申请并授权1项发明专利，出版了2本英文书，6人次参加国内外学术交流，邀请3人次国际学者访问交流，培养了1名博士、3名硕士研究生顺利毕业。