The Study On Integration Of Gravities Anomaly In South Korea And Its Vicinities By Using Spherical Cap Harmonic Analysis

The gravity anomalies that observed by ground and shipborne survey and calculated from GRACE satellite are combined by using spherical cap harmonic analysis (SCHA). In this study, ground gravity data from Korea Institute of Geoscience and Mineral Resource(KIGAM) and shipborne gravity data from National Ocean Research Institute( NORI) and Korea Ocean Research and Development institute(KORDI) were used. L-2 level GRACE Gravity Model (GGM02C) was also used for satellite gravity anomaly. The ground and shipborne surveyed data were combined and gridded using Krigging method with 0.05 degree interval and GRACE data were also gridded using the same method with 0.05 degree to harmonize with the resolution of SCHA that has coefficient up to 80. Generalized Minimal Residual(GMRES) inversion method was implemented for calculating the coefficients of SCHA using the gridded ground and satellite gravity anomalies that had 0 km and 50 km altitude, respectively. The results of inversion method showed good correlation of 0.950 and 0.995 with original ground and satellite data. The gravity anomaly using SCHA satisfies Laplace's equation, therefore, using these SCHA coefficients, gravity anomaly can be calculated at any altitude. In this study, gravity anomaly was calculated from 10 km to 60 km altitude and each altitude. very stable results were shown. The ground and shiphome gravity data that have higher resolution and satellite data in long wavelength are harmonized well with SCHA coefficients and successfully applied in South Korea area. If more continuous survey and muti-altitude surveyed data like airborne data available, more precise gravity anomaly can be acquired using SCHA method.