Precise Gravimetric Determination of Geoid in the Vicinity of Japan



1. Introduction
2. Gravimetric Determination of Geoid
  2.1 Basic Formulas of Geoid Determination
  2.2 Derivation of spherical Computation Using the FFT Method
    (a)Local Determination of a Precision Geoid with Reference to a Global Geopotential Model
    (b)Indifect Effect Correction to the Geoid Height
    (c)Spherical Approximation of Stokes' Function
3. Surface Gravity Data Processing
  3.1 Land Gravity Data
    (a)GSI Data
    (b)Data Collected by Nagoya University
    (c)Reference Frame Conversion from the Tokyo Datum to the Geocentric GRS80
  3.2 Ocean Surface Gravity Data
    (a)Data Set
    (b)Data Editing
  3.3 Data Gridding with Continuous Curvature Splines in Tension
  3.4 Result of the Estimated Gravity Anomaly Field in the Vicinity of Japan
  3.5 Discussions
    (a) Errors of the Gridded Gravity Anomalies
    (b) Comparison of Gravity Anomalies with Satellite-altimetrically Derived Model
4. Precision Geoid in the Vicinity of Japan
  4.1 Results of a Gravimetrically Determined Geoid
  4.2 Estimation of Errors of the Geoid Model JGEOID93
    (a) Effects of the Errors of Gravity Anomaly Data
    (b) Effects of Position and Frame Conversion Errors
    (c) Systematic Errors Caused by the FFT Method of Stokes' Integration
    (d) Long Wavelength Errors due to the Procedure or Inherent to the Reference Model
  4.3 Comparison of the Geoid Model with ORI89
  4.4 Comparison with the GPS/leveling Measurements
    (a) Nagoya
    (b) Bousou
    (c) Kinki
    (d) Southwestern Japan
    (e) Shizuoka
    (f) VLBI data
  4.5 Discussions
5. Geodetic/Geophysical Implications of the Geoid
  5.1 Isostasy Status
  5.2 Relationship between the Topography and the Geoid
  5.3 Different Features of the Geoid and the Gravity Anomaly Changes Perpendicular to the Trench Axes
6. Concluding Remarks