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Regional Models

Japan (JGEOID98)

  Author: Y. Kuroishi     Created: 1998    Resp: T. Yahagi (GSI)  
      Status: PRIVATE    
The JGEOID98 model is an improved gravimetric geoid for Japan of the Geographical Survey Institute ( It is constructed on a 3'x3' grid in the non-tidal system and it is referred to the GRS80 ellipsoid in the ITRF89 frame. About 570000 ship gravity data are improved by adjusting them for about 50000 cross-over errors. The geoid determination is based on the remove-restore technique, using EGM96 as the reference geopotential model and applying a 1D-FFT method. Compared with GPS/levelling benchmarks, JGEOID98 shows improvement over JGEOID93 by 29 % in short wavelength, and a significant tilt reduction. The remaining trend can be partly explained by gravity errors: overestimation of gravity induced from EGM96 east off Hokkaido and underestimation south off Taiwan.

Y. Kuroishi (2001). An improved gravimetric geoid for Japan, JGEOID98, and relationships to marine gravity data. Journal of Geodesy, 74(11), pp. 745-755.