2009年7月22日日全食重力效应研究

发布时间：2018-11-16 08:05

【摘要】：日全食是一种罕见的天文现象。日全食之所以受重视，更主要的原因是它的天文观测价值巨大。太阳和地球有着极为密切的关系，日食可以为研究太阳和地球的关系提供良好的机会。近几年连续发生了多次日全食现象，为我们对日全食现象的研究提供了很好的机会。但是，由于日全食出现的不规律性及观测仪器的限制，对其研究的进展缓慢。早期人们曾用傅科摆在日全食期间进行观测并发现其摆动角度有所变化，后来用精度较高的重力仪发现日全食期间出现“重力谷”现象。本研究在此背景下进行探索，探究日全食期间的重力变化。本论文主要开展以下工作： 1、介绍重力测量方法与重力仪器，重点关注本次研究所用到的超导重力仪及Gphone重力仪。 2、简述重力固体潮基础理论，引潮力及引潮力位。 3、着重介绍重力数据预处理及固体潮改正方法。研究气压对重力观测影响的改正。利用气压导纳值法扣除重力气压效应，并用日全食期间超导重力仪数据进行实例分析。实验表明，虽然气压对重力影响较小，通常只有1-2个微伽，但超导重力仪重力残差数据显示其与气压变化有显著的相关性，有利于利用气压变化时间序列直接改正气压对超导重力仪观测数据的影响。 4、利用前面介绍的理论及改正方法处理2009年7月22日日全食期间的重力观测数据，分析实验结果，，探索日全食重力效应。数据处理具体思路为：首先，对数据进行重力固体潮改正，利用调和分析法确定固体潮潮汐因子，再根据合成潮汐法扣除重力固体潮影响。然后采用气压导纳值法对重力残差数据进行气压改正。再根据以往观测到的“重力谷“时间范围确定截止频率，对残差数据进行通带滤波，进一步去除重力固体潮以及背景噪声的影响，以便分离出重力异常信号。从2009年日全食重力观测数据的处理结果得出：未发现此次日全食期间有幅度较大的“重力谷”或者明显重力异常存在。
[Abstract]:Total solar eclipse is a rare astronomical phenomenon. The more important reason for the total solar eclipse is its astronomical value. Solar eclipse provides a good opportunity to study the relationship between the sun and the earth. In recent years, there have been many total eclipses, which provides us with a good opportunity to study the total solar eclipse. However, due to the irregularity of total solar eclipse and the limitation of observational instruments, the progress of its research is slow. In the early period, the Fourier pendulum was used to observe the total solar eclipse and its swing angle was found to be changed. Later, the phenomenon of "gravity valley" appeared during the total solar eclipse by using a high precision gravimeter. In this context, this study explores the gravity changes during the total solar eclipse. The main work of this thesis is as follows: 1. The gravity measurement method and the gravity instrument are introduced, and the superconducting gravimeter and Gphone gravimeter used in this research are focused on. 2. The basic theory, tidal force and tidal potential of gravity solid tide are briefly described. 3. The preprocessing of gravity data and the correction method of solid tide are introduced emphatically. The correction of the influence of atmospheric pressure on gravity observation is studied. The effect of gravity pressure is deducted by the method of barometric admittance, and an example is analyzed with the data of superconducting gravimeter during total solar eclipse. The experiments show that although the pressure has little effect on gravity, usually there are only 1-2 microgals, the gravity residuals of the superconducting gravimeter show a significant correlation with the variation of the pressure. It is advantageous to correct the influence of pressure on the observation data of superconducting gravimeter by using the time series of atmospheric pressure change. 4. The gravity observation data during the total solar eclipse on July 22, 2009 are processed by using the theory and correction method, the experimental results are analyzed, and the gravity effect of the total solar eclipse is explored. The main ideas of data processing are as follows: first, the gravity tide is corrected, the factor of tide is determined by harmonic analysis method, and then the influence of gravity tide is deducted according to the method of composite tide. Then the barometric admittance method is used to correct the gravity residual data. The cut-off frequency is determined according to the time range of "gravity valley" observed in the past, the residual data is filtered by pass band, and the influence of gravity tide and background noise is removed further, in order to separate gravity anomaly signal. From the processing results of the total solar eclipse gravity observation data in 2009, it is concluded that there are no large "gravity valleys" or obvious gravity anomalies during the total solar eclipse.
【学位授予单位】：中国地震局地震研究所
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P125.11

【参考文献】