A GOCE only gravity model GOSG01S and the validation of GOCE related satellite gravity models

Xu, Xinyu; Zhao, Yuchen; Reubelt, T.; Tenzer, Róbert

doi:10.1016/j.geog.2017.03.013

Cited by 19 publications

(19 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this paper, we derive the coseismic gravity and gravity gradient changes by evaluating the differences between a post-earthquake gravity field model and a pre-earthquake one from GOCE data; namely, we first recover gravity field models from the Gravity field and steady state Ocean Circulation Explorer Satellite Gravity Gradient (GOCE SGG) observations before and after the 2011 Tohoku-Oki earthquake. Here, we provide a brief description of the data processing strategies of recovering a gravity field model from GOCE SGG observations (more details can be found in Xu et al [33]).…”

Section: Recovering Gravity Field Model From Goce Sgg Observationsmentioning

confidence: 99%

“…The component V ij of the second-order gravity gradient tensor (GGT) is normally defined in the Local North-Oriented Frame (LNOF) with the x-axis pointing north, the y-axis pointing west and the z-axis up, as follows [33]: C nm S nm (1) where the indices i and j define the gravitational gradient components (xx, yy, zz, xy, . .…”

Section: Recovering Gravity Field Model From Goce Sgg Observationsmentioning

confidence: 99%

“…Then, we can determine the geopotential coefficients C nm and S nm , exploiting the least-squares (LS) method. However, the observed GGT of the GOCE mission is given in the Gradiometer Reference Frame (GRF), so we should transform the observations from the GRF to the LNOF by using the rotation matrix R L G [33]. However, the accuracies of the V xy and V yz components are lower than those of the other components, so they will contaminate the high-precision components ( Equation 1instead of transforming the GGT observations in GRF.…”

Section: Recovering Gravity Field Model From Goce Sgg Observationsmentioning

confidence: 99%

See 2 more Smart Citations

GOCE-Derived Coseismic Gravity Gradient Changes Caused by the 2011 Tohoku-Oki Earthquake

Ding

Zhao

et al. 2019

Remote Sensing

Self Cite

View full text Add to dashboard Cite

In contrast to most of the coseismic gravity change studies, which are generally based on data from the Gravity field Recovery and Climate Experiment (GRACE) satellite mission, we use observations from the Gravity field and steady-state Ocean Circulation Explorer (GOCE) Satellite Gravity Gradient (SGG) mission to estimate the coseismic gravity and gravity gradient changes caused by the 2011 Tohoku-Oki Mw 9.0 earthquake. We first construct two global gravity field models up to degree and order 220, before and after the earthquake, based on the least-squares method, with a bandpass Auto Regression Moving Average (ARMA) filter applied to the SGG data along the orbit. In addition, to reduce the influences of colored noise in the SGG data and the polar gap problem on the recovered model, we propose a tailored spherical harmonic (TSH) approach, which only uses the spherical harmonic (SH) coefficients with the degree range 30–95 to compute the coseismic gravity changes in the spatial domain. Then, both the results from the GOCE observations and the GRACE temporal gravity field models (with the same TSH degrees and orders) are simultaneously compared with the forward-modeled signals that are estimated based on the fault slip model of the earthquake event. Although there are considerable misfits between GOCE-derived and modeled gravity gradient changes (ΔVxx, ΔVyy, ΔVzz, and ΔVxz), we find analogous spatial patterns and a significant change (greater than 3σ) in gravity gradients before and after the earthquake. Moreover, we estimate the radial gravity gradient changes from the GOCE-derived monthly time-variable gravity field models before and after the earthquake, whose amplitudes are at a level over three times that of their corresponding uncertainties, and are thus significant. Additionally, the results show that the recovered coseismic gravity signals in the west-to-east direction from GOCE are closer to the modeled signals than those from GRACE in the TSH degree range 30–95. This indicates that the GOCE-derived gravity models might be used as additional observations to infer/explain some time-variable geophysical signals of interest.

show abstract

Section: Recovering Gravity Field Model From Goce Sgg Observationsmentioning

confidence: 99%

Section: Recovering Gravity Field Model From Goce Sgg Observationsmentioning

confidence: 99%

Section: Recovering Gravity Field Model From Goce Sgg Observationsmentioning

confidence: 99%

See 1 more Smart Citation

GOCE-Derived Coseismic Gravity Gradient Changes Caused by the 2011 Tohoku-Oki Earthquake

Ding

Zhao

et al. 2019

Remote Sensing

Self Cite

View full text Add to dashboard Cite

show abstract

“…In most cases the SST part comes from high-low Global Navigation Satellite System (GNSS) observations between the spacecraft carrying the gradiometer and GNSS spacecraft, and in such cases, the orbits are usually done in Precise Kinematic mode, which means that there are no equations of motion involved and the positions are determined independently at each observation point. [20,35,36,37]. The squareroot variance (or RMS) is plotted as a function of the geopotential degree (the value of 2n in the symbol J 2n of a multipole).…”

Section: Conceptual Shortcomings Of Differencing the Lowest Even Zonamentioning

confidence: 99%

Reply to “A comment on “A test of general relativity using the LARES and LAGEOS satellites and a GRACE Earth gravity model, by I. Ciufolini et al.””

Ciufolini

Ignazio²,

Pavlis³

et al. 2018

Eur. Phys. J. C

View full text Add to dashboard Cite

In 2016, we published “A test of general relativity using the LARES and LAGEOS satellites and a GRACE Earth’s gravity model. Measurement of Earth’s dragging of inertial frames [ 1 ]”, a measurement of frame-dragging, a fundamental prediction of Einstein’s theory of General Relativity, using the laser-ranged satellites LARES, LAGEOS and LAGEOS 2. The formal error, or precision, of our test was about 0.2% of frame-dragging, whereas the systematic error was estimated to be about 5%. In the 2017 paper “A comment on “A test of general relativity using the LARES and LAGEOS satellites and a GRACE Earth’s gravity model by I. Ciufolini et al.”” by L. Iorio [ 2 ] (called I2017 in the following), it was incorrectly claimed that, when comparing different Earth’s gravity field models, the systematic error in our test due to the Earth’s even zonal harmonics of degree 6, 8, 10 could be as large as 15%, 6% and 36%, respectively. Furthermore, I2017 contains other, also incorrect, claims about the number of necessary significant decimal digits of the coefficients used in our test (claimed to be nine), in order to eliminate the largest uncertainties in the even zonals of degree 2 and 4, and about the non-repeatability of our test. Here we analyze and rebut those claims in I2017.

show abstract

“…The acceleration method is based on Newton's equation of motion, which balances the gravitational vector with satellite accelerations in the inertial reference frame [14,15]. The principle of acceleration approach is simple and has been successfully applied to CHAMP, GRACE, and GOCE SST-hl data analysis [14][15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Gravity Field Model Determination Based on GOCE Satellite Point-Wise Accelerations Estimated from Onboard Carrier Phase Observations

et al. 2019

Remote Sensing

Self Cite

View full text Add to dashboard Cite

GPS-based, satellite-to-satellite tracking observations have been extensively used to elaborate the long-scale features of the Earth’s gravity field from dedicated satellite gravity missions. We proposed compiling a satellite gravity field model from Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) satellite accelerations directly estimated from the onboard GPS data using the point-wise acceleration approach, known as the carrier phase differentiation method. First, we composed the phase accelerations from the onboard carrier phase observations based on the sixth-order seven-point differentiator, which can eliminate the carrier phase ambiguity for Low Earth Orbiter (LEO). Next, the three-dimensional (3D) accelerations of the GOCE satellite were estimated from the derived phase accelerations as well as GPS satellite ephemeris and precise clock products. Finally, a global gravity field model up to the degree and order (d/o) 130 was compiled from the 71 days and nearly 2.5 years of 3D satellite accelerations. We also recovered three gravity field models up to d/o 130 from the accelerations derived by differentiating the kinematic orbits of European Space Agency (ESA), Graz, and School of Geodesy and Geomatics (SGG), which was the orbit differentiation method. We analyzed the accuracies of the derived accelerations and the recovered gravity field models based on the carrier phase differentiation method and orbit differentiation method in time, frequency, and spatial domain. The results showed that the carrier phase derived acceleration observations had better accuracy than those derived from kinematic orbits. The accuracy of the recovered gravity field model based on the carrier phase differentiation method using 2.5 years observations was higher than that of the orbit differentiation solutions for degrees greater than 70, and worse than Graz-orbit solution for degrees less than 70. The cumulative geoid height errors of carrier phase, ESA-orbit, and Graz-orbit solutions up to degree and order 130 were 17.70cm, 21.43 cm, and 22.11 cm, respectively.

show abstract

A GOCE only gravity model GOSG01S and the validation of GOCE related satellite gravity models

Cited by 19 publications

References 14 publications

GOCE-Derived Coseismic Gravity Gradient Changes Caused by the 2011 Tohoku-Oki Earthquake

GOCE-Derived Coseismic Gravity Gradient Changes Caused by the 2011 Tohoku-Oki Earthquake

Reply to “A comment on “A test of general relativity using the LARES and LAGEOS satellites and a GRACE Earth gravity model, by I. Ciufolini et al.””

Gravity Field Model Determination Based on GOCE Satellite Point-Wise Accelerations Estimated from Onboard Carrier Phase Observations

Contact Info

Product

Resources

About