Evaluation of Recent GRACE and GOCE Satellite Gravity Models and Combined Models Using GPS/Leveling and Gravity Data in China

2014 ◽  
pp. 67-74 ◽  
Author(s):  
Jiancheng Li ◽  
Weiping Jiang ◽  
Xiancai Zou ◽  
Xinyu Xu ◽  
Wenbin Shen
Keyword(s):  
Gravity Data ◽  
Gravity Models ◽  
Satellite Gravity ◽  
Combined Models ◽  
Gps Leveling ◽  
Goce Satellite

Evaluation of the latest GOCE GGMs in support of regional geoid modeling over Greece

2021 ◽  
Author(s):  
Georgios S. Vergos ◽  
Ilias N. Tziavos ◽  
Dimitrios A. Natsiopoulos ◽  
Elisavet G. Mamagiannou ◽  
Eleftherios A. Pitenis
Keyword(s):  
Maximum Degree ◽  
Gravity Data ◽  
Ground Truth ◽  
Satellite Gravity ◽  
Disturbing Potential ◽  
Geopotential Models ◽  
Potential Functionals ◽  
Geoid Computation ◽  
Goce Satellite

<p>In the frame of the GeoGravGOCE project, funded by the Hellenic Foundation for Research Innovation, GOCE Satellite Gravity Gradiometry (SGG) data are to be used for regional geoid and gravity field refinement as well as for potential determination in the frame of the International Height Reference Frame (IHRF). An inherent step in the geoid computation with either stochastic or spectral methods is the reduction of the related disturbing potential functionals within the well-known Remove-Compute-Restore (RCR) procedure. In this work we evaluate the latest, Release 6 (R6), satellite only and combined Global Geopotential Models (GGMs) which rely solely on GOCE and on land gravity data. The evaluation is performed over the established network of 1542 GPS/Levelling benchmarks over Greece mainland (BMs), which have been used in the past for the evaluation of GOCE GGMs. We employ the spectral enhancement approach, during which the GOCE-based GGMs are evaluated every one degree to the maximum degree of expansion coupled by EGM2008 and high-frequency RTM effects. This synthesis resolves wavelengths corresponding to maximum degree 216,000, hence the omission error is at the few mm-level. TIM-R6, DIR-R6, GOCO06s and XGM2019e are evaluated using EGM2008 residuals to the GPS/Levelling as the ground truth. From the results achieved, the optimal combination degree of a GOCE-only GGM augmented with EGM2008 is selected to be used in the sequel as reference field for the practical determination of the gravimetric geoid over Greece.</p>

New insights into the Andean crustal structure between 32° and 34°S from GOCE satellite gravity data and EGM2008 model

2014 ◽  
Vol 399 (1) ◽  
pp. 183-202 ◽  
Author(s):  
O. Alvarez ◽  
M. E. Gimenez ◽  
M. P. Martinez ◽  
F. Lince Klinger ◽  
C. Braitenberg
Keyword(s):  
Crustal Structure ◽  
Gravity Data ◽  
Satellite Gravity ◽  
Goce Satellite

scholarly journals An oceanographer’s guide to GOCE and the geoid

2006 ◽  
Vol 3 (5) ◽  
pp. 1543-1568 ◽  
Author(s):  
C. W. Hughes ◽  
R. J. Bingham
Keyword(s):  
Gravitational Field ◽  
Measurement System ◽  
Spherical Harmonic ◽  
Gravity Data ◽  
Reference Ellipsoid ◽  
Satellite Mission ◽  
Satellite Gravity ◽  
Ocean Models ◽  
Goce Satellite ◽  
The Way

Abstract. A review is given of the geodetic concepts necessary for oceanographers to make use of satellite gravity data to define the geoid, and to interpret the resulting product. The geoid is defined, with particular attention to subtleties related to the representation of the permanent tide, and the way in which the geoid is represented in ocean models. The usual spherical harmonic description of the gravitational field is described, together with the concepts required to calculate a geoid from the spherical harmonic coefficients. A brief description is given of the measurement system in the GOCE satellite mission, scheduled for launch shortly, followed by a description of a reference ellipsoid with respect to which the geoid may be calculated. Finally, a recipe is given for calculation of the geoid relative to any chosen ellipsoid, given a set of spherical harmonic coefficients and defining constants.

Assessment of the GOCE-Based Global Gravity Models in Canada

GEOMATICA ◽  
2012 ◽  
Vol 66 (2) ◽  
pp. 125-140 ◽  
Author(s):  
E. Sinem Ince ◽  
Michael G. Sideris ◽  
Jianliang Huang ◽  
Marc Véronneau
Keyword(s):  
Great Lakes ◽  
Rocky Mountains ◽  
Spherical Harmonic ◽  
Gravity Models ◽  
Geopotential Model ◽  
Third Generation ◽  
Combined Models ◽  
Gps Leveling ◽  
Global Gravity Models ◽  
Geoid Undulations

The aim of this study is to test the first, second and third generation GOCE geoid solutions, obtained from the first 2, 8 and 18-month observations, respectively. These solutions are assessed over Canada and for two sub-regions (the Great Lakes and Rocky Mountains). The Canadian GPS/leveling-derived geoid heights are used as independent control values in the assessment of the GOCE geoid models. The study is conducted in two steps. First, the geoid models are computed from satellite-only models and truncated to different spherical harmonic degrees. These models are compared with the GPS/leveling geoid heights which are reduced to the same spectral band as the satellite models by EGM2008 predicted frequency components higher than the truncation degrees. The results suggest that the GOCE models show a full power of signal up to about spherical harmonic degree 180. Moreover, the second and third generation GOCE models (with the exception of the direct approach models) provide better agreement with the GPS/leveling-derived geoid undulations than the first generation models due to the longer observation period. The second step involves the combination of the two third generation GOCE models with terrestrial data. These models are tested against to the GPS/leveling-derived geoid undulations in full spectrum. EGM2008 global geopotential model and Canadian gravimetric geoid model CGG2005 are also included in the comparisons to measure improvement provided by the GOCE models. The GOCE-combined models yielded GPS/leveling results that are comparable with those obtained from EGM2008 and CGG2005 models. The best comparative results with the combined models give standard deviations of 4.8 cm, 6.0 cm and 12.2 cm for the Great Lakes, Rocky Mountains and Canada, respectively. These results indicate that the third generation GOCE models conform to the Canadian terrestrial gravity data from degrees 90 to 180. The new generation models show evident improvement over the first and second generation models.

scholarly journals An Oceanographer's Guide to GOCE and the Geoid

Ocean Science ◽  
2008 ◽  
Vol 4 (1) ◽  
pp. 15-29 ◽  
Author(s):  
C. W. Hughes ◽  
R. J. Bingham
Keyword(s):  
Gravitational Field ◽  
Spherical Harmonic ◽  
Gravity Data ◽  
Reference Ellipsoid ◽  
Sea Surface ◽  
Dynamic Topography ◽  
Satellite Mission ◽  
Satellite Gravity ◽  
Ocean Models ◽  
Goce Satellite

Abstract. A review is given of the geodetic concepts necessary for oceanographers to make use of satellite gravity data to define the geoid, and to interpret the resulting product. The geoid is defined, with particular attention to subtleties related to the representation of the permanent tide, and the way in which the geoid is represented in ocean models. The usual spherical harmonic description of the gravitational field is described, together with the concepts required to calculate a geoid from the spherical harmonic coefficients. A brief description is given of the measurement system in the GOCE satellite mission, scheduled for launch shortly. Finally, a recipe is given for calculation of the ocean dynamic topography, given a map of sea surface height above a reference ellipsoid, a set of spherical harmonic coefficients for the gravitational field, and defining constants.

Crustal Thickness of Chinese Mainland Inversed by GOCE Satellite Gravity Data

2014 ◽  
Vol 568-570 ◽  
pp. 288-291
Author(s):  
Hai Jun Xu ◽  
Hu Rong Duan ◽  
Jian Ye Zhou
Keyword(s):  
Comparative Analysis ◽  
Gravity Anomaly ◽  
Gravity Data ◽  
Crustal Thickness ◽  
Geoid Height ◽  
Chinese Mainland ◽  
Satellite Gravity ◽  
Inversion Result ◽  
Goce Satellite

GOCE satellite gravity data is often used to compute gravity anomaly and geoid height. In the paper, GOCE gravity data is used to inverse the crustal thickness of Chinese mainland (E70°~130°, N20°~50°) in this paper. In order to test the reliability of the result, the computing result is compared with previous studies. The comparative analysis shows that the inversion result by GOCE gravity data has higher resolution and has good consistence with the previous studies.

scholarly journals Sequential inversion of GOCE satellite gravity gradient data and terrestrial gravity data for the lithospheric density structure in the North China Craton

Solid Earth ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 1121-1144
Author(s):  
Yu Tian ◽  
Yong Wang
Keyword(s):  
North China ◽  
Gravity Data ◽  
Initial Density ◽  
Gravity Gradient ◽  
Density Structure ◽  
Satellite Gravity ◽  
Density Data ◽  
The North ◽  
Density Anomaly ◽  
Goce Satellite

Abstract. The North China Craton (NCC) is one of the oldest cratons in the world. Currently, the destruction mechanism and geodynamics of the NCC remain controversial. All of the proposed views regarding the issues involve studying the internal density structure of the NCC lithosphere. Gravity field data are among the most important data in regard to investigating the lithospheric density structure, and gravity gradient data and gravity data each possess their own advantages. Given the different observational plane heights between the on-orbit GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) satellite gravity gradient and terrestrial gravity and the effects of the initial density model on the inversion results, sequential inversion of the gravity gradient and gravity are divided into two integrated processes. By using the preconditioned conjugate gradient (PCG) inversion algorithm, the density data are calculated using the preprocessed corrected gravity anomaly data. Then, the newly obtained high-resolution density data are used as the initial density model, which can serve as constraints for the subsequent gravity gradient inversion. Several essential corrections are applied to the four gravity gradient tensors (Txx, Txz, Tyy, Tzz) of the GOCE satellite, after which the corrected gravity gradient anomalies (T′xx, T′xz, T′yy, T′zz) are used as observations. The lithospheric density distribution result within the depth range of 0–180 km in the NCC is obtained. This study clearly illustrates that GOCE data are helpful in understanding the geological settings and tectonic structures in the NCC with regional scale. The inversion results show that in the crust the eastern NCC is affected by lithospheric thinning with obvious local features. In the mantle, the presented obvious negative-density areas are mainly affected by the high-heat-flux environment. In the eastern NCC, the density anomaly in the Bohai Bay area is mostly attributed to the extension of the Tancheng–Lujiang major fault at the eastern boundary. In the western NCC, the crustal density anomaly distribution of the Qilian block is consistent with the northwest–southeast strike of the surface fault belt, whereas such an anomaly distribution experiences a clockwise rotation to a nearly north–south direction upon entering the mantle.

Joint inversion of the lithospheric density struture in the North China Craton based on GOCE satellite gravity gradient data and surface gravity data

2020 ◽  
Author(s):  
Yu Tian ◽  
Yong Wang
Keyword(s):  
North China ◽  
Joint Inversion ◽  
Gravity Data ◽  
Initial Density ◽  
Gravity Gradient ◽  
Density Structure ◽  
Satellite Gravity ◽  
Density Data ◽  
The North ◽  
Goce Satellite

<p>The North China Craton (NCC) is one of the oldest cratons in the world. Currently, the destruction mechanism and geodynamics of the NCC still remain controversial. All of the proposed views regarding the issues involve studying the internal density structure of the NCC lithosphere. Gravity field data are one of the most important data in regard to investigating the lithospheric density structure, the gravity gradient data and the gravity data possess their own advantages. Given the inconsistency of the on orbit GOCE satellite gravity gradient and surface gravity observation plane height, also effects of the initial density model upon of the inversion results, the joint inversion of gravity gradient and gravity are divided into two integrated processes. By using the preconditioned conjugate gradient (PCG) inversion algorithm, the density data are calculated using the preprocessed remaining gravity anomaly data. The newly obtained high resolution density data are then used as the initial density model, which can be served as the constraints for the subsequent gravity gradient inversion. Downward continuation, terrain correction, interface undulation correction and long wavelength correction are performed for the four gravity gradient tensor data(<strong>T</strong><sub>xx</sub>，<strong>T</strong><sub>xz</sub>，<strong>T</strong><sub>yy</sub>，<strong>T</strong><sub>zz</sub>)of the Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite,  after which the remaining gravity gradient anomaly data(<strong>T</strong>'<sub>xx</sub>，<strong>T</strong>'<sub>xz</sub>，<strong>T</strong>'<sub>yy</sub>，<strong>T</strong>'<sub>zz</sub>) are used as the new observation quantity. Finally, the ultimate lithospheric density distribution within the depth range of 0–180 km in the NCC is obtained using the same PCG algorithm.</p>

scholarly journals Evaluation of GGMs Based on the Terrestrial Gravity Data of Gravity Disturbance and Moho Depthin Afar, Ethiopia

2021 ◽  
Vol 56 (3) ◽  
pp. 78-100
Author(s):  
Eyasu Alemu
Keyword(s):  
Gravity Data ◽  
Gravity Models ◽  
Moho Depth ◽  
Equal Distribution ◽  
Terrestrial Gravity ◽  
Global Gravity ◽  
Gravity Disturbances ◽  
Combined Models ◽  
Global Gravity Models ◽  
Best Fit

Abstract To estimate Moho depth, geoid, gravity anomaly, and other geopotential functionals, gravity data is needed. But, gravity survey was not collected in equal distribution in Ethiopia, as the data forming part of the survey were mainly collected on accessible roads. To determine accurate Moho depth using Global Gravity Models (GGMs) for the study area, evaluation of GGMs is needed based on the available terrestrial gravity data. Moho depth lies between 28 km and 32 km in Afar. Gravity disturbances (GDs) were calculated for the terrestrial gravity data and the recent GGMs for the study area. The model-based GDs were compared with the corresponding GD obtained from the terrestrial gravity data and their differences in terms of statistical comparison parameters for determining the best fit GGM at a local scale in Afar. The largest standard deviation (SD) (36.10 mGal) and root mean square error (RMSE) (39.00 mGal) for residual GD and the lowest correlation with the terrestrial gravity (0.61 mGal) were obtained by the satellite-only model (GO_CONS_GCF_2_DIR_R6). The next largest SD (21.27 mGal) and RMSE (25.65 mGal) for residual GD were obtained by the combined gravity model (XGM2019e_2159), which indicates that it is not the best fit model for the study area as compared with the other two GGMs. In general, the result showed that the combined models are more useful tools for modeling the gravity field in Afar than the satellite-only GGMs. But, the study clearly revealed that for the study area, the best model in comparison with the others is the EGM2008, while the second best model is the EIGEN6C4.

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