Earth's Gravity Field Derived from Grace Satellite Tracking Data

Abstract

An Earth's gravity field model IGGGRACE01S has been derived from 141 days of GRACE tracking data, including K‐band, accelerometer, and satellite orbit data. The model resolves the geoid with an accuracy of about 0.012m at a resolution of 500m half‐wavelengths, it improves the accuracy of the gravity field model in the long‐ to medium‐wavelength part (< 80 degree) in comparison with the pre‐CHAMP model. Comparing the coefficients of IGGGRACE01S, EIGEN‐GRACE02S, EIGEN‐CHAMP03S and EGM96 models, the result shows that the coefficients of IGGGRACE01S are much closer to those of EIGEN‐GRACE02S, and very different to those of the other two models. Comparing the geoid undulations and gravity anomalies derived from IGGGRACE01S, EIGEN‐GRACE02S and EGM96 models, the results indicate that the IGGGRACE01S solution is much closer to EIGENGRACE02S solution, and there exist large differences between IGGGRACE01S and EGM96 in Antarctica region. Comparing the gravity anomalies derived from IGGGRACE01S (72 degree) with NIMA gravity anomalies data (2.5° × 2.5°), the standard deviation is 4.8 mGal in China mainland region.

Water Storage Changes in Three Gorges Water Systems Area Inferred from Grace Time‐Variable Gravity Data

“…Firstly, as in previous works, the comparison is done between the inversion results and the weighting-averaged results of the CPC models in the same Gaussian averaging radius, defined in Eq. (2). Note that the CPC results are calculated from Eq.…”

“…The NASA/DLR Gravity Recovery and Climate Experiment (GRACE) mission was launched in March 2002, opening a new era in the mapping of the gravity field to high spatio-temporal resolution [1,2] . The observed gravity changes can be utilized to estimate global and regional water storage changes by inversion [3∼10] .…”

Precise Establishment of the Next‐generation Earth Gravity Field Model From Hip‐3s Based on Combination of Inline and Pendulum Satellite Formations

“…However, the disadvantage of the single-formation satellite gravity mission (e.g. Gravity Recovery and Climate Experiment (GRACE) inline tracking mode (Zhang et al, 2004;Reigber et al, 2005;Shen et al, 2005;Tapley et al, 2005;Cheng and Xu, 2006;Zheng et al, 2006Zheng et al, , 2011Zheng et al, , 2015Zhou et al, 2006;Xu, 2008)) is that the spatial and temporal resolution of satellite observations can not be synchronously improved. According as the Heisenberg Uncertainty Principle (HUP), the product of spatial resolution S R and temporal resolution T R of satellite measurements is constant, i.e.…”

Precise and Rapid Recovery of the Earth's Gravity Field from the Next‐Generation GRACE Follow‐On Mission using the Residual Intersatellite Range‐Rate Method

“…The detailed investigations of the fine structure and time-variable characteristics of the Earth's gravitational field not only are the requirements for space geodesy, geophysics, geodynamics, oceanography, etc., but also will provide important information for resource exploration, environmental protection and disaster monitoring. Based on the outstanding performances of accurately measuring the Earth's gravitational field in the medium-long-wavelength (static) and long-wavelength (time-variable) ranges from the existing GRACE mission (Zhang et al, 2004;Shen et al, 2005;Cheng and Xu, 2006;Zhou et al, 2006;Zheng et al, 2006Zheng et al, , 2008aZheng et al, , 2009aZheng et al, , 2009bZheng et al, , 2009cZheng et al, , 2011, the next-generation satellite gravity mission GRACE Follow-on has been proposed by the American National Aeronautics and Space Administration (NASA) to precisely map the Earth's static and time-variable gravitational fields with unprecedented spatial resolution in the medium-short-wavelength (static) and medium-long-wavelength (time-variable) ranges (Rummel, 2003;Sneeuw, 2005;Bender et al, 2008;Zheng et al, 2008bZheng et al, , 2009dZheng et al, , 2010Zheng et al, , 2013Wiese et al, 2009Wiese et al, , 2012Loomis et al, 2012). Table 1, the twin GRACE Follow-On satellites, flying in an almost circular, nearly polar and low-Earth orbit, will precisely measure the intersatellite range with an accuracy of 10 −6 ∼ 10 −8 m and intersatellite range-rate with a precision of 10 −7 ∼ 10 −9 m/s by the ILR system, the orbital position and orbital velocity by the high-Earth-orbit GPS satellites and the nonconservative force with an accuracy of 10 −11 ∼ 10 −13 m/s 2 by the accelerometer, and will accurately compensate the non-conservative force by the Drag-Free Control System (DFCS).…”