Probing the Lunar Interior using Lunar-A mission data

本研究的目的是利用日本宇宙航行科学研究所的月球A使命的数据来探测月球的内部结构。但由于设备研制方面的一些问题，这一使命将推迟到2003年。因此，我们无法达到最初的目的，而是准备了一些软件工具和数据库，以便在数据可用时能够快速分析月球A数据。（1）月球地震模型根据Okuchi和Takahashi（1994）提出的月球形成的岩石学解释，计算了月球内部的地震剖面。所得剖面与Apollo地震资料的结果一致。该模型将用作分析月球A数据的参考模型。(2)阿波罗月球地震记录数据库我们建立了一个阿波罗月球地震记录数据库。月球-A使命的地震仪比阿波罗项目的地震仪灵敏10倍。然而，月球-A地震计只有两个。因此，阿波罗计划的数据集的帮助将是重要的月球-A使命。该数据库可通过http：//www.geo.titech.ac.jp/lunarA/进入。(3)散射波剖面的再现已知月球地震波剖面具有长的散射波持续时间。我们可以使用地壳非常浅的部分的简单分层结构来检索特征。在分析Lunar-A数据时，我们必须考虑到这一点。(4)通过对深月地震激发的地震波的综合计算，找到了一种确定月核大小的有效方法。尽管有长散射波的污染，pP和Pdiff/PKP之间的间隔时间是可检测的。时间对月球核心的大小很敏感。注意，合成计算非常繁重。因此，我们改进了计算方法（DSM方法），使其更有效。

The purpose of this study was to probe the Lunarinternal structure using data of Lunar-A mission whichis promoted by Institute of Space and Astronautical Science, Japan. However, the mission will be delayed until 2003 because of some troubles in development of devices. So we could not achieve the initial purpose, and, instead, we prepared some software tools and database to be able to analyze quickly Lunar-A data when the data are available. The following are the results(1) Lunar seismic modelWe calculated seismic profile of the Lunar interior on basis of the petrologically accessible scenario of the Lunar forming by Okuchi and Takahashi (1994). The resultant Profile is consistent with the result from apollo seismic data. The model will be used as a reference model on analysis of Lunar-A data.(2) database of apollo lunar seismic recordsWe made a database of apollo lunar seismic records. The seismometers of the Lunar-A mission are 10 times more sensitive than those of the Apollo project. However, The number of the Lunar-A seismometer is only two. So the aid of the data sets of the apollo project will be important to the Lunar-A mission. The database are accessible via http : //www.geo.titech.ac.jp/lunarA/.(3) reproduction of scattering wave profileLunar seismic wave profiles are know to have long duration of scattered waves. We could retrieve the feature using a simple stratified structure in the very shallow part of the crust. On analysis of Lunar-A data, we must take it into consideration.(4) determination of the Lunar core sizeBy synthetic calculation of seismic waves induced by deep moon quakes, we found an effective method to clear the Lunar core size. The interval time between pP and Pdiff/PKP is detectable in spite of contamination of long scattering waves. The time is sensitive to the Lunar core size. Note the synthetic calculations are very heavy. So we improve the calculation method (the DSM method) to be more efficient.