Abstract
AbstractXGM2019e is a combined global gravity field model represented by spheroidal harmonics up to degree and order (d/o) 5399, corresponding to a spatial resolution of 2′ (~ 4 km). As data sources, it includes the satellite model GOCO06s in the longer wavelength range up to d/o 300 combined with a ground gravity grid which also covers the shorter wavelengths. The ground data consist over land and ocean of gravity anomalies provided by courtesy of NGA (15′ resolution, identical to XGM2016) augmented with topographically derived gravity information over land (EARTH2014). Over the oceans, gravity anomalies derived from satellite altimetry are used (DTU13 with a resolution of 1′). The combination of the satellite data with the ground gravity observations is performed by using full normal equations up to d/o 719 (15′). Beyond d/o 719, a block-diagonal least squares solution is calculated for the high-resolution ground gravity data (from topography and altimetry). All calculations are performed in the spheroidal harmonic domain. In the spectral band up to d/o 719, the new model shows a slightly improved behaviour in the magnitude of a few mm RMS over land as compared to preceding models such as XGM2016, EIGEN6c4 or EGM2008 when validated with independent geoid information derived from GNSS/levelling. Over land and in the spectral range above d/o 719, the accuracy of XGM2019e marginally suffers from the sole use of topographic forward modelling, and geoid differences at GNSS/levelling stations are increased in the order of several mm RMS in well-surveyed areas, such as the US and Europe, compared to models containing real gravity data over their entire spectrum, e.g. EIGEN6c4 or EGM2008. However, GNSS/levelling validation also indicates that the performance of XGM2019e can be considered as globally more consistent and independent of existing high-resolution global models. Over the oceans, the model exhibits an enhanced performance (equal or better than preceding models), which is confirmed by comparison of the MDT’s computed from CNES/CLS 2015 mean sea surface and the high-resolution geoid models. The MDT based on XGM2019e shows fewer artefacts, particularly in the coastal regions, and fits globally better to DTU17MDT which is considered as an independent reference MDT.
Publisher
Springer Science and Business Media LLC
Subject
Computers in Earth Sciences,Geochemistry and Petrology,Geophysics
Reference32 articles.
1. Andersen O, Knudsen P, Kenyon S, Factor J, Holmes S (2013) The DTU13 global marine gravity field—first evaluation. Ocean Surf Topogr Sci Team Meet, Boulder, Colorado
2. Brockmann JM, Schubert T, Mayer-Gürr T, Schuh W-D (2019) The Earth’s gravity field as seen by the GOCE satellite: an improved sixth release derived with the time-wise approach (GO_CONS_GCF_2_TIM_R6). GFZ Data Serv. https://doi.org/10.5880/ICGEM.2019.003
3. Drinkwater MR, Floberghagen R, Haagmans R, Muzi D, Popescu A (2003) GOCE: ESA’s first earth explorer core mission. In: Beutler G et al (eds) Earth gravity field from space—from sensors to earth science, space sciences series of ISSI, vol 18. Kluwer Academic Publishers, Dordrecht, pp 419–432. ISBN 1-4020-1408-2
4. Fecher T, Pail R, Gruber T, the GOCO Consortium (2017) GOCO05c: a new combined gravity field model based on full normal equations and regionally varying weighting. Surv Geophys 38:571–590. https://doi.org/10.1007/s10712-016-9406-y
5. Förste C, Bruinsma S, Abrikosov O, Flechtner F, Marty J-C, Lemoine J-M, Dahle C, Neumayer H, Barthelmes F, König R et al (2014) EIGEN-6C4-The latest combined global gravity field model including GOCE data up to degree and order 1949 of GFZ Potsdam and GRGS Toulouse. EGU Gen Assembly Conf Abstr 16:3707
Cited by
158 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献