INVERSE VENING-MEINESZ FORMULA AND DEFLECTION-GEOID FORMULA - APPLICATIONS TO THE PREDICTIONS OF GRAVITY AND GEOID OVER THE SOUTH CHINA SEA

Using the spherical harmonic representations of the earth's disturbing potential and its functionals, we derive the inverse Vening Meinesz f ormula, which converts deflection of the vertical to gravity anomaly u sing the gradient of the H function. The deflection-geoid formula is a lso derived that converts deflection to geoidal undulation using the g radient of the C function. The two formulae are implemented by the 1D FFT and the 2D FFT methods. The innermost zone effect is derived. The inverse Vening Meinesz formula is employed to compute gravity anomalie s and geoidal undulations over the South China Sea using deflections f rom Seasat, Geosat, ERS-1 and TOPEX//POSEIDON satellite altimetry. The 1D FFT yields the best result of 9.9-mgal rms difference with the shi pborne gravity anomalies. Using the simulated deflections from EGM96, the deflection-geoid formula yields a 4-cm rms difference with the EGM 96-generated geoid. The predicted gravity anomalies and geoidal undula tions can be used to study the tectonic structure and the ocean circul ations of the South China Sea.