Research Of Gravitational Effect During Total Solar Eclipse Of22July2009

Total solar eclipse is a phenomenon which happens rarely. Its huge astronomicalobservation value is the main reason for total solar eclipse been such valued. The solar eclipsecan be a good opportunity to study the relationship between the sun and the earth, these twoplanets has a very close relationship. Solar eclipses have taken place several times in recent years,which provide us with excellent opportunities to study it. However, little progress was madebecause the total solar eclipse occurs irregularly and the instruments only provide low accuracyobservation. In early stage, people found the swing angle changed during eclipse by usingpendulums. Later, people made measurement by highly precision spring gravimeter, evensuperconducting gravimeter, and mysteries of nature are revealed step by step. The study showssome facts, aiming to find the gravity changes during total solar eclipse.This paper mainly undertakes the following tasks:1、Sketch the basic theory of the solid earth tide, tide generating force and tide-generatingpotential; Tidal gravity data preprocessing and correction method is emphatically introduced.2、Introduce gravity measurement and gravity instruments, institute of focus on thesuperconducting gravimeter and Gphone gravimeter.3、Research on the correct of pressure influence to the gravity observations. Atmosphericadmittances method is used to deduct the gravity pressure effect and make superconductinggravimeter data during the total solar eclipse as an example. Experiments show that, although thepressure influence of gravity is very small, usually only one or two micro gals, but the gravityresidual data of superconducting gravimeter shows a significant correlation with the pressurechange, and it is helpful to use the pressure change time series to correct superconductinggravimeter observation data directly.4、Use the theory and correction method described above to deal with the gravityobservation data of total solar eclipse on July22,2009, analyze the residuals to find out whetherthere were gravity changes during the total solar eclipse or not.The specific thoughts are as follows: First, correct the gravity tide, determine the gravitytidal factor by using the harmonic analysis method, and then deduct the influence of the tidalgravity according to synthetic tidal method. Second, deduct the gravity pressure effect with theatmospheric admittances method. Last, determine the filter frequency base on the time range of‘gravity valley’ observed before, fatherly removal influence of solid earth tide and the impact of background noise, so as to isolate the gravity anomaly signal.The result is made after a series processes on the gravity data observed: there is no ‘gravityvalley’ or apparent change in2009total solid eclipce.