【作者】 曲保安；

【导师】 王喜珍；

【作者基本信息】 中国地震局地球物理研究所 ， 地球探测与信息技术， 2011， 硕士

【摘要】 月球作为人类深空探测的第一站,成为各国新一轮的探测和研究热点。我国的探测工程于2004年立项,分三期实施,2020年前的月球探测工程以无人探测为主。为了探测月球的深部结构,计划在二期或三期工程中配置月震仪载荷。由于条件所限,配置的月震仪载荷拟安装在着陆器内。由于着陆器系统的引入,将对接收的月震信号产生影响。这种影响是什么样的,如何消除或抑制这种影响,是在探测前需要弄清楚的,对月球探测目标的实现有着重要影响。为了对着陆器系统的影响进行分析,我们进行了模拟实验,即将一台地震仪置于一个类着陆器支架之上,另一台置于支架之下的地面上,用可控震源激发振动信号,即认为地面地震仪记录为输入信号,置于支架上的地震仪记录为输出信号,通过比较二者之差异来模拟和分析着陆器系统的影响。论文首先选取了三种类型的多个月震记录,即深源月震、浅源月震和陨石撞击,分别在时域和频域对其特征进行了研究。其主要特征为：深源月震波形频率成分集中在0.3-0.6Hz,浅源月震波形频率成分集中于2.5-10Hz,陨石撞击波形频率成分集中在0.5-6Hz。为了更好的了解其特征,也选取了类似类型的地震事件,采用类似的方法进行分析,结果表明,二者的频谱特性基本相同。分析并处理模拟实验数据是本论文的核心内容。模拟实验数据来自三种不同的系统或介质,即四方型支架、三脚架和粘土层。分别分析了四方型支架位置效应、三脚架和四方型支架系统效应、粘土层效应以及支架系统特性与信号强弱及环境温度关系。根据模拟装置系统的影响特征,采用陷波器、幅值恢复、相位校正等方法进行支架系统影响的抑制、消除以及信号还原。最后以地震参数计算、类单台定位和结构反演为参考标准对复原信号进行了验证,从震级计算、初动方向和到时等方面进行分析,结果表明采用的信号提取方法是有效的、可行的。最后,作者认为,月震定位、月震震源机制反演、月球内部更精细结构反演等用的震相到时,测定震级所用的记录波形最大面波幅值等都能过通过信号提取得到近似地面记录的数据。将月震仪置于着陆器内进行月震事件记录的思路和方法可行。更多还原

【Abstract】 The Moon, the first station of human’s deep space exploration, has become a new focus of exploration and research in various countries. The Lunar Explorer Project was established in China in 2004. The project was planned to implement in three periods which were all unmanned before 2020. The lunar seismograph was intended to be loaded to the Moon in period two or three for the detection of inner structure of the Moon. However the lunar seismograph was planned to be fixed in the lander owing to condition limit. Thus the effect of the Lander support system was introduced in the lunar seismograph records. Analysis and research of such effect is what demanded before the moonquake exploration.To analyze the effect of the Lander supporting system, a simulation experiment was designed and implemented. A seismograph was placed on the simulation supporting system, another seismograph was deployed on the ground just under the supporting system. A vibroseis was prepared to stimulate vibration signal which was considered as quake signal. Thus the record of the seismograph on the ground is the input, the record of the seismograph on the simulation supporting system is the output, the difference between the input and output is the effect of the supporting system.Firstly, some moonquake of The Apollo Lunar Surface Experiment Package were selected and researched. These moonquake events can be classified into three types, they are deep moonquake, shallow moonquake and meteoroid impact. These moonquake records were analyzed in time domain and frequency domain, and the frequency spectrum characteristics of the three types moonquakes was summarized respectively. The frequency components of deep moonquakes mainly lay between 0.3Hz and 0.6Hz while 2.5Hz to 10Hz for the shallow moonquakes and 0.5Hz to 6Hz for meteoroid impacts. For better understanding of the characteristics of moonquakes, the certain analogous earthquakes were selected and analyzed in the same way. After the comparison of frequency spectrum characteristics of moonquakes and earthquakes in analogous type, the conclusion that they are basically identical was proposed.The core content is analysis and processing of simulation experiment data. The data of the experiment is composed by three different systems or medium. They are four-leg framework system, tripod system and clay layer. According the three parts, four aspects were analyzed. They are position effect on the four-leg framework, system characteristics of tripod and four-leg framework, effect of clay layer and the relationship between system characteristics of supporting system and signal intensity or ambient temperature. Adaptive notch filter, amplitude recovery and phase correction was adopted as signal extraction method according to the effect characteristic of simulation system. Finally, seismic parameter calculation, resembling single-station event location and structure inversion were choosed as the standard for signal recovery effect. The result of magnitude, first motion direction and arrival time comparation shows that the signal extraction method is effective and feasible.Finally, the arrival time for moonquake location, moonquake focal mechanism inversion, inner Moon fine structure inversion and the amplitude of the recording for moonquake magnitude calculation and so on can be acquired from recording of the seismograph on supporting system after signal extraction. So the idea of recording moonquake with lunar seismograph fixed in the Lander is practical.更多还原