HR: 1330h
AN: G32A-0738    [PDF]
TI: Improved Gravimetric Geoid Model for Japan From Terrestrial Data and Altimetric Gravity Model
AU: * Kuroishi, Y
EM: yuki@gsi.go.jp
AF: Geographical Survey Institute, Space Geodesy Laboratory, 1 Kitasato, Tsukuba, 305-0811 Japan
AB: An improved gravimetric geoid model for Japan is developed by combining an altimetric gravity model, KMS02 with terrestrial gravity data. Additional terrestrial gravity data were newly obtained in some data gaps for previous geoid models: ship data in the western part of Seto Inland Sea and land gravity data in south and east Hokkaido, where the latest gravimetric geoid model for Japan, JGEOID2000 shows relatively large errors at short wavelengths. In addition, medium wavelength signals of gravity from KMS02 are retrieved and combined by filtering based on wavelets. The combination significantly reduces systematic errors of JGEOID2000 gravity/geoid models derived from ship data, at medium wavelengths around Hokkaido Island. Moreover, recently-released global geopotential models from the GRACE mission, EIGEN-GRACE01S by GFZ and GGM01 by CSR are used as a foundation for 1D-FFT computation of Stokes integral in a remove-restore manner. Those models themselves show improved performance over the Japanese islands in terms of geoid heights when compared with GPS/leveling geoid heights throughout the islands. When we change the maximum degree of the spherical harmonics used and merge them with higher degree harmonics of EGM96 (up to degree and order 360), those geopotential models seem to work best at degree 90. Resulting geoid models are compared and evaluated with GPS/leveling geoid heights.
DE: 1200 GEODESY AND GRAVITY
SC: Geodesy [G]
MN: 2003 Fall Meeting