Development of the new Korean Precise Geoid Model and its Application
Abstract
The low density and precision of land gravity data were pointed out as a problem of degrading the precision of the Korean geoid model. To overcome the problems, new land gravity data showing the homogeneous distribution and high precision are being obtained since 2008. In 2009, airborne gravity data was collected to cover the mountainous and coastal area. Also, the new version of global geopotential models (e.g. EIGEN-6C4, XGM2016) are available. In this study, gravimetric geoid was newly developed by the "Remove-Restore" technique using more than 12,000 points of land gravity data. In addition, airborne, shipborne and DTU10 altimeter gravity data, as well as the XGM2016 geopotential model were applied for modeling. Then, as a final product of the study, the hybrid geoid called KNGeoid18 was modeled by fitting gravimetric geoid to total 2,791 points of GNSS/Leveling data which are located over whole Korean peninsula. The degree of fit of the KNGeoid18 was calculated to be about 2.3cm. The necessity of a local geoid model is to determine the orthometric height time and cost-efficiently. To check the applicability of the geoid model, GNSS surveying was conducted on the 12 points located in the mountainous area and the orthometric heights were determined by GNSS-orthometric height determination technique. When comparing orthometric heights using TBC, LGO, and Giodis, all points show smaller than 5cm of difference. Thus, it was concluded that the precise orthometric height would be determined by GNSS surveying and the local geoid model when the target precision is about 3~5cm level.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.G33B0669L
- Keywords:
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- 1217 Time variable gravity;
- GEODESY AND GRAVITY;
- 1219 Gravity anomalies and Earth structure;
- GEODESY AND GRAVITY;
- 1244 Standards and absolute measurements;
- GEODESY AND GRAVITY;
- 1294 Instruments and techniques;
- GEODESY AND GRAVITY