Height connection across sea by using satellite altimetry data sets, ellipsoidal heights, astrogeodetic deflections of the vertical, and an Earth Gravity Model
Jianbo Wang , Xinmin Qi , Kai Luo , Zhengyuan Li , Ruikang Zhou , Jinyun Guo
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引用次数: 3
Abstract
Islands and the mainland are separated by seas, and the distances between them might be so long that the height on the mainland cannot be exactly translated to the islands, resulting in different height systems on the mainland and the islands. In this study, we used astrogeodetic deflections of the vertical and ellipsoidal heights of points on the mainland and island near their coastlines to implement height connection across sea areas. First, the modeled gravity and modeled astrogeodetic vertical deflections of segmentation points along connecting routes over the sea between the mainland and the island were determined by Earth Gravity Model (EGM), and the ellipsoidal heights of segmentation points were determined by the satellite altimetry data sets. Second, we used a linear interpolation model to increase the precision of the vertical deflections of segmentation points. Third, we computed the geopotential difference of points between the mainland and the island using a method derived from geopotential theory and the astronomical leveling principle. Finally, we estimated the normal height of the point on the island using the geopotential-difference iterative computation approach. Using observed data of normal heights, ellipsoidal heights, and astrogeodetic vertical deflections referring to height sites in Qingdao, Shandong Province, we conducted a numerical experiment involving the normal height connection across sea regions. We determined the data of the ellipsoidal heights and gravity of segmentation points along the connecting route across the water in the numerical experiment using DTU10. The distance of the height connection across the sea was approximately 10.5 km. According to China's official leveling specifications, the experimental results met the criterion of third-class leveling precision.
期刊介绍:
Geodesy and Geodynamics launched in October, 2010, and is a bimonthly publication. It is sponsored jointly by Institute of Seismology, China Earthquake Administration, Science Press, and another six agencies. It is an international journal with a Chinese heart. Geodesy and Geodynamics is committed to the publication of quality scientific papers in English in the fields of geodesy and geodynamics from authors around the world. Its aim is to promote a combination between Geodesy and Geodynamics, deepen the application of Geodesy in the field of Geoscience and quicken worldwide fellows'' understanding on scientific research activity in China. It mainly publishes newest research achievements in the field of Geodesy, Geodynamics, Science of Disaster and so on. Aims and Scope: new theories and methods of geodesy; new results of monitoring and studying crustal movement and deformation by using geodetic theories and methods; new ways and achievements in earthquake-prediction investigation by using geodetic theories and methods; new results of crustal movement and deformation studies by using other geologic, hydrological, and geophysical theories and methods; new results of satellite gravity measurements; new development and results of space-to-ground observation technology.