The Refined Gravity Field Models for Height System Unification in China

A unified height datum is essential for global geographic information resource construction, ecological environment protection, and scientific research. The goal of this paper to derive the geopotential value Chinese (CNHD) in order realize unification China. estimation usually depends on high-precision gravity field models (GFMs). satellite missions Gravity Recovery Climate Experiment (GRACE) steady-state Ocean Circulation Exploration (GOCE) provide high-accuracy, medium–long-wavelength spectra, but satellite-only GFMs are limited medium–long wavelengths, which will involve omission errors. To compensate errors GFMs, a spectral expansion approach used obtain refined using EGM2008 (Earth Gravitational Model 2008) residual terrain model (RTM) technique. evaluated by high-quality GNSS/leveling data, results show that quasi-geoid accuracy DIR_R6_EGM2008_RTM China has optimal and, compared with DIR_R6 model, improved 9.6 cm 21.8 cm, improvement ranges 35.7% 55.8%, respectively. Finally, estimated be equal 62,636,853.29 m2s−2 respect reference level defined W0 = 62,636,853.4 utilizing 1908 datapoints.