Description:
PIGEOID2021 is a purely gravimetric quasi-geoid model covering the whole Paracel Islands in the northwestern South China Sea. The quasi-geoid is referred to the GRS80 ellipsoid and extends from 15.27°N to 18.23°N and from 110.59°E to 113.30°E with a grid spacing of 30" in both the latitudinal and longitudinal directions. PIGEOID2021 is computed using localised airborne gravity anomalies (with an accuracy of 1.44 mGal at a resolution of 3 km) under the framework of the remove-compute-restore method, where XGM2019e_2159 (truncated to d/o 1080) is used as the reference model and the residual terrain model is applied for smoothing local gravity field at very short scales (< 3 km). The residual gravity field is parameterized using Poisson wavelets by assuming white noise of observations. Comparisons with altimeter-derived geometric quasi-geoid heights retrieved from Jason-2, CryoSat-2, and SARAL show the misfits of PIGEOID2021 are within 5 cm. Further analysis shows PIGEOID2021 reduces the bubble-like errors over island areas by a magnitude exceeding 6 cm compared to existing global geopotential models.
Model Citation:
Y. Wu, A. Abulaitijiang, O.B. Andersen, X. He, Z. Luo, H. Wang (2021). The gravimetric quasi-geoid of Paracel Islands: PIGEOID2021. V 1.0. GFZ Data Services. DOI: 10.5880/isg.2021.011
Reference:
Y. Wu, A. Abulaitijiang, O.B. Andersen, X. He, Z. Luo, H. Wang (2021). Refinement of mean dynamic topography over island areas using airborne gravimetry and satellite altimetry data in the northwestern South China Sea. Journal of Geophysical Research:Solid Earth, 126(8), e2021JB021805. DOI: 10.1029/2021JB021805
Digital object identifier:
DOI: 10.5880/isg.2021.011 (quasi-geoid in ISG format)
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