Research on Calculation Method of Vertical Deflection Based on Gravity Data

Summary The vertical deflection indicates the inclination of the geoid to the earth ellipsoid, reflecting the mass distribution and migration of materials within the earth, therefore, the study of vertical deflection is an important work in geophysics. Based on Stokes boundary value theory, this paper calculates vertical deflection through gravity data. First, the gravity data of aerial survey over South Dakota, North America is processed, and the free-air gravity anomaly in the region is obtained through latitude correction and altitude correction, then the free-air gravity anomaly data is processed based on Stokes integral to determine the Geoid in this region, finally, the vertical deflection value of each measuring point in the study area is obtained through spatial difference. The calculation values were also compared with the vertical deflection of the EGM2008 model, and the comparison results indicate that the method used in this study can achieve the correct vertical deflection from airborne gravity data.