基于嫦娥三号探月雷达的月球次表层介电常数反演及成分分析

发布时间：2018-04-15 16:20

本文选题：月球次表层 + 随机等效介质　；参考：《吉林大学》2016年硕士论文

【摘要】：在月球遥感领域,由于相关研究对月球卫星雷达数据的雷达波特性以及月表以下的反射面及深度探测还存在不同的认识和相反的结论,如何通过科学手段充分了解月表不同岩性单元的电性特性及其深度上的变化梯度,实现月球次表层雷达波传播过程建模和解决前人不同认识和相反结论显得尤为重要。通过对嫦娥三号第一通道探月雷达数据进行读取、拼接、增益以及滤波等处理可看出,在180ns以及640ns附近都存在一个明显的反射界面。根据时深转换公式得到两个分层界面分别在月表下10m及40m处,并且分析认为10m以内是月壤层。通过建立不同自相关长度a、b以及模糊度因子r条件下的随机等效介质模型,分析影响模型建立的因素。基于随机等效介质理论和FDTD数值模拟计算方法选择合适的参数,建立月球随机等效介质模型,利用锥形函数对模型进行优化,得到高精度的月球三层随机介质正演模型和探月雷达电磁响应剖面图,为后续月球次表层介电常数反演模型验证提供可靠的正演数据。为验证介电常数反演方法,研究有限带宽阻抗(BLIMP)反演理论。以探月雷达随机介质模型正演数据为基础,通过多次反演,实现有限带宽阻抗反演模型参数选取及介电常数反演。从反演结果发现,介电常数反演结果与模型设置的介电常数整体上吻合较好,介电常数分布情况较为一致,说明有限带宽阻抗反演方法可用于嫦娥三号探月雷达数据的介电常数反演。以嫦娥三号第一通道探月雷达数据为基础,利用验证后的有限带宽阻抗(BLIMP)反演方法,反演二维随机介质的介电常数。反演结果显示,不同分层界面明显,层内介电常数分布特性体现出一定的随机性,0~10m以内的介电常数值在2.3310~3.9086之间,与月壤真实样品介电常数对比较为吻合;10~40m以内的介电常数范围为6.5119~8.4897,大部分介电常数值在7左右。40m以下的介电常数范围为7.5010~8.4449,大部分介电常数值在8左右,与月球玄武岩真实样品测量值对比较为一致。基于月壤等效介质模型理论,利用月壤介电常数反演结果,模拟反演月壤平均矿物含量,其中,斜长石含量范围为20.93%~29.04%;橄榄石含量范围为37.28%~45.02%;单斜辉石含量范围为50.44%~60.96%;钛铁矿含量范围为6.79%~8.08%。将月壤矿物含量反演结果与Apollo和Luna登月点采集的月壤真实样品矿物含量、凌宗成等人利用APXS数据反演的月壤矿物成分以及基于M3数据反演的月表矿物成分进行对比分析表明,月壤斜长石、辉石以及钛铁矿的反演效果较好,橄榄石反演结果存在一定的偏差。从内蒙古锡林浩特、黑龙江阿尔山、黑龙江五大连池、河北张家口、黑龙江镜泊湖和吉林省辉南地区,选取18块玄武岩作为模拟月岩样品,开展介电常数以及岩石切面占空比(岩石切面单位面积内气孔的总面积)测量。通过分析模拟样品介电常数与岩石切面占空比的关系,得到模拟月岩样品的介电常数随着切面占空比的增加而减小,说明月表以下深度越大,月岩的物质结构越致密。将有限带宽阻抗反演结果与模拟月岩样品介电常数的测量值进行对比分析,反演结果中10~40m以内的介电常数值大部分在7左右,与内蒙古锡林浩特地区的XL-01、XL-03、XL-12以及河北张家口地区的L5-04测量结果比较接近,40m以下的介电常数值大部分在8左右,与河北张家口地区的L5-01以及L4-09测量结果较为吻合。这不仅说明有限带宽阻抗反演结果具有一定的可靠性,也说明月表以下10~40m以内的月岩产状和岩相与内蒙古锡林浩特地区以及河北张家口地区的玄武岩类似,部分岩石内部存在一定孔隙,还有一部分岩石结构较致密。40m以下的月岩产状和岩相与河北张家口地区的玄武岩类似,岩石物质结构致密,几乎没有孔隙存在。
[Abstract]:In the field of Remote Sensing Research on the moon, because the moon satellite radar data and radar wave reflection characteristics of the lunar surface and the depth of exploration and there are different opinions and the opposite conclusion, how to fully understand the change of gradient electric characteristics of different lithological units and its surface depth through scientific means, realize the lunar subsurface radar wave propagation model and solve the previous different understanding and the opposite conclusion is particularly important. Read through the mosaic, Chang'e three lunar first channel radar data, gain and filtering can be seen in the vicinity of 180ns and 640ns are a clear reflection of the deep transformation formula according to the interface. Two layered interface respectively lunar 10m and 40m, and analyzed that within 10m is a regolith layer. Through the establishment of different autocorrelation length a, B and fuzzy factor under the condition of R Random equivalent medium model, influence factors analysis model. Simulation calculation method of selecting suitable parameters of numerical random equivalent medium theory and based on FDTD, a lunar random equivalent medium model, the model was optimized by using cone function, high accuracy moon three layer random medium forward model and lunar radar electromagnetic response profile, provide forward the reliable data for the subsequent lunar subsurface dielectric constant inversion model validation. As the dielectric constant inversion method to verify the dielectric, the limited bandwidth of the impedance (BLIMP) inversion theory. The lunar radar random medium model is based on data through multiple parameters inversion, finite bandwidth impedance inversion model is selected and the dielectric constant of inversion found. From the inversion results, dielectric constant and dielectric constant of the inversion results on the whole are in good agreement with the model set, the dielectric constant distribution situation is consistent, The finite bandwidth impedance inversion method for dielectric constant inversion Chang'e three lunar radar data. The Chang'e three lunar radar based on the data of the first channel, using limited bandwidth to verify the impedance (BLIMP) inversion method, dielectric constant inversion of two-dimensional random medium. The inversion results show that different interfacial layer obviously. Dielectric constant distribution reflects a certain randomness, the dielectric constant value less than 0~10m between 2.3310~3.9086, and the lunar regolith sample real permittivity of dielectric constant for anastomosis; range within 10~40m 6.5119~8.4897, most of the dielectric constant dielectric constant in the range of about 7.40m below 7.5010~8.4449 and most of the dielectric constant at about 8, and the real measured value of lunar basalt samples for comparison. The lunar regolith model theory based on equivalent medium, using regolith dielectric constant inversion. Results the average mineral content, inversion of lunar regolith simulation the plagioclase content is in the range of 20.93%~29.04%; the content of olivine in the range of 37.28%~45.02% content in the range of 50.44%~60.96%; clinopyroxene; ilmenite content is in the range of 6.79%~8.08%. the lunar soil mineral content inversion with Apollo and Luna landing point acquisition of lunar soil samples real mineral content, Ling Zongcheng et al use of lunar soil mineral composition of the inversion of APXS data and M3 data inversion of lunar minerals based on the comparative analysis shows that the regolith plagioclase, pyroxene ilmenite and better inversion effect, olivine inversion results have certain deviation from Inner Mongolia. Xilinhaote, Heilongjiang, Arxan, Heilongjiang, Wudalianchi, Hebei, Zhangjiakou, Heilongjiang, Lake Jingpo and Jilin Huinan area, select 18 as a piece of basalt rock samples to carry out simulation, dielectric constant and duty ratio (rock section The total area of the rock section in unit area of stomata) measurement. Through the analysis of simulated sample permittivity and rock section of duty, the dielectric constant of simulated rock samples decreases with the increase of the duty ratio section, indicating greater depth of the lunar lunar material structure, the measurement results will be more compact. The limited bandwidth impedance inversion and Simulation of rock samples values of the dielectric constant were analyzed, the inversion results in 10~40m within the dielectric constant value most in about 7, and the Inner Mongolia Xilinhaote area XL-01, XL-03, L5-04 and XL-12 measurement results are close to the Hebei Zhangjiakou area, the dielectric constant value below 40m mostly in about 8 with the Hebei, Zhangjiakou area L5-01 and L4-09 measurement results are consistent. It shows not only the limited bandwidth impedance inversion results has certain reliability, also said the moon surface to 10~40m Within the rock occurrence and lithofacies and Inner Mongolia Xilinhaote area and Hebei area of Zhangjiakou like Xuan Wuyan, there are some parts of the rock pore, and a part of the rock structure is more dense than.40m rock occurrence and lithofacies and Hebei Zhangjiakou area of Xuan Wuyan is similar to that of rock material is compact, almost no pores exist.

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P184.5

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