scholarly journals Determination of geopotential of local vertical datum surface

2003 ◽  
Vol 6 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Wei Ziqing ◽  
Jiao Wenhai
Keyword(s):  
Vertical Datum ◽  
Local Vertical Datum

scholarly journals Preliminary Unification of Kronsztadt86 Local Vertical Datum with Global Vertical Datum

2015 ◽  
Vol 97 (1) ◽  
pp. 103-111 ◽  
Author(s):  
Adam Łyszkowicz ◽  
Joanna Kuczyńska-Siehień ◽  
Monika Biryło
Keyword(s):  
Systematic Error ◽  
Sufficient Accuracy ◽  
Satellite Networks ◽  
Satellite Observations ◽  
Gravity Potential ◽  
Best Value ◽  
Vertical Datum ◽  
Normal Heights ◽  
Low Efficiency ◽  
Local Vertical Datum

AbstractThe study concerns computation of the gravity potential difference between the Kronsztadt86 datum and the global vertical datum. This method is based on the use of ellipsoidal heights from satellite observations, normal heights obtained from the conducted leveling campaign and quasigeoid/ellipsoid separations computed based on the EGM2008 model. The obtained results indicate that there are substantial differences in the estimated value of the parameter ΔW, computed from three different satellite networks: POLREF, EUVN-DA and ASG-EUPOS. The parameter was determined with sufficient accuracy and the applied systematic error model has low efficiency. The computations reveal that the best value of ΔW for the territory of Poland is 0.43 m2s-2.

scholarly journals Application of the BEM approach for a determination of the regional marine geoid model and the mean dynamic topography in the Southwest Pacific Ocean and Tasman Sea

2012 ◽  
Vol 2 (1) ◽  
pp. 8-14 ◽  
Author(s):  
R. Tenzer ◽  
R. Čunderlík ◽  
N. Dayoub ◽  
A. Abdalla
Keyword(s):  
Pacific Ocean ◽  
Dynamic Topography ◽  
Geoid Model ◽  
Mean Dynamic Topography ◽  
Southwest Pacific ◽  
Tasman Sea ◽  
Marine Gravity ◽  
The Mean ◽  
Local Vertical Datum

Application of the BEM approach for a determination of the regional marine geoid model and the mean dynamic topography in the Southwest Pacific Ocean and Tasman SeaWe apply a novel approach for the gravimetric marine geoid modelling which utilise the boundary element method (BEM). The direct BEM formulation for the Laplace equation is applied to obtain a numerical solution to the linearised fixed gravimetric boundary-value problem in points at the Earth's surface. The numerical scheme uses the collocation method with linear basis functions. It involves a discretisation of the Earth's surface which is considered as a fixed boundary. The surface gravity disturbances represent the oblique derivative boundary condition. The BEM approach is applied to determine the marine geoid model over the study area of the Southwest Pacific Ocean and Tasman Sea using DNSC08 marine gravity data. The comparison of the BEM-derived and EGM2008 geoid models reveals that the geoid height differences vary within -25 and 18 cm with the standard deviation of 6 cm. The DNSC08 sea surface topography data and the new marine geoid are then used for modelling of the mean dynamic topography (MDT) over the study area. The local vertical datum (LVD) offsets estimated at 15 tide-gauge stations in New Zealand are finally used for testing the coastal MDT. The average value of differences between the MDT and LVD offsets is 1 cm.

scholarly journals Determination of the new vertical datum of Slovenia

2019 ◽  
Vol 63 (01) ◽  
pp. 13-26
Author(s):  
Oskar Sterle ◽  
Božo Koler
Keyword(s):  
Vertical Datum

scholarly journals A Quasigeoid-Derived Transformation Model Accounting for Land Subsidence in the Mekong Delta towards Height System Unification in Vietnam

2020 ◽  
Vol 12 (5) ◽  
pp. 817
Author(s):  
Dinh Toan Vu ◽  
Sean Bruinsma ◽  
Sylvain Bonvalot ◽  
Dominique Remy ◽  
Georgios S. Vergos
Keyword(s):  
Mekong Delta ◽  
Equipotential Surface ◽  
Transformation Model ◽  
Gravity Potential ◽  
Third Order ◽  
Vertical Datum ◽  
Height System ◽  
Gravimetric Quasigeoid ◽  
Local Vertical Datum

A vertical offset model for Vietnam and its surrounding areas was determined based on the differences between height anomalies derived from 779 Global Navigation Satellite System (GNSS)/levelling points and those derived from a dedicated high-resolution gravimetric-only quasigeoid model called GEOID_LSC. First, the deterministic transformation model to effectively fit the differences between the quasigeoid and GNSS/levelling heights was based on a third-order polynomial model. Second, the residual height anomalies have been interpolated to a grid employing Least-Squares Collocation. Finally, the distortions were restored to the residual grid. This model can be used for combination with a gravimetric quasigeoid model in GNSS levelling. The quality of GNSS/levelling data in Vietnam was analyzed and evaluated in this study. The annual subsidence rate from ALOS-1 was also used to analyze the effects of subsidence on the quality of GNSS/levelling data in the Mekong Delta. From this we made corrections to improve the accuracy of GNSS/levelling data in this region. The offset model was evaluated using cross-validation technique by comparing with GNSS/levelling data. Results indicate that the offset model has a standard deviation of 5.9 cm in the absolute sense. Based on this offset model, GNSS levelling can be carried out in most of Vietnam’s territory complying third-order levelling requirements, while the accuracy requirements for fourth-order levelling networks is met for the entire country. This model in combination with the developed gravimetric quasigeoid model should also contribute to the modernization of Vietnam’s height system. We also used high-quality GNSS/levelling data and the determined quasigeoid model to determine the geopotential value W0 for the Vietnam Local Vertical Datum. The gravity potential of the Vietnam Local Vertical Datum is estimated equal to W 0 LVD = 62,636,846.81 ± 0.70 m2s−2 with the global equipotential surface realized by the conventional value W0 = 62,636,853.4 m2s−2.

scholarly journals Estimation of vertical datum offset for the South African vertical datum, in relation to the international height reference system

2021 ◽  
Vol 65 (02) ◽  
pp. 282-297
Author(s):  
Matthews Siphiwe Mphuthi ◽  
Patroba Achola Odera
Keyword(s):  
South Africa ◽  
South African ◽  
Reference System ◽  
Tide Gauge ◽  
Cape Town ◽  
Gravity Potential ◽  
The South ◽  
Vertical Datum ◽  
Port Elizabeth ◽  
Local Vertical Datum

The vertical offset and the geopotential value over South Africa is estimated on the four fundamental benchmarks in relation to the international height reference system (IHRS). It is estimated to obtain discrepancies between the South African local vertical datum (W_P) and the global vertical datum (W_0). A single-point-based geodetic boundary value problem (GBVP) approach was used following Molodensky theory for estimating the height anomalies from the disturbing potential (T_P) using Bruns’s formula. The gravity potential at each tide gauge benchmark (TGBM) in South Africa deviates from the potential of the global reference surface by 0.589,-1.993,-2.593 and 2.154 m2s-2 for Cape Town, Port Elizabeth, East London and Durban, respectively. The corresponding vertical datum offsets between the international height reference system and the four fundamental benchmarks over South Africa are 6.013, -20.347, -26.478, and 21.996 cm for Cape Town, Port Elizabeth, East London and Durban, respectively. These offsets can be used for the unification of the South African vertical datum at the four tide gauge benchmarks in a manner that is consistent to the international height reference system.

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