Accuracy assessment of GOCE-based geopotential models and their use for modelling the gravimetric quasigeoid - A case study for Poland

Abstract

Abstract:The GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) has signifi cantly upgraded the knowledge on the Earth gravity fi eld. In this contribution the accuracy of height anomalies determined from Global Geopotential Models (GGMs) based on approximately 27 months GOCE satellite gravity gradiometry (SGG) data have been assessed over Poland using three sets of precise GNSS/levelling data. The fi ts of height anomalies obtained from 4 th release GOCE-based GGMs to GNSS/levelling data were discussed and compared with the respective ones of 3 rd release GOCE-based GGMs and the EGM08. Furthermore, two highly accurate gravimetric quasigeoid models were developed over the area of Poland using high resolution Faye gravity anomalies. In the fi rst, the GOCE-based GGM was used as a reference geopotential model, and in the second -the EGM08. They were evaluated with GNSS/levelling data and their accuracy performance was assessed. The use of GOCE-based GGMs for recovering the long-wavelength gravity signal in gravimetric quasigeoid modelling was discussed.

Gravity field modelling and gravimetry

“…Africa, South America and South-East Asia. An accuracy of 2.1-3.3 cm of height anomalies obtained from 4 th release GOCE-based GGMs at maximum d/o 200 could be expected at any place on the Earth, except the poles and their adjacent areas that were not flown over by the GOCE satellite (Godah et al, 2014a).…”

“…Poland, but such areas could be suitable to evaluate GOCE-based GGMs, in particular to estimate the accuracy of height anomalies obtained from those models. On the other hand, when 1-2 cm accuracy of geoid at d/o 200 obtained from GOCE mission is achieved, the GOCE-based GGMs might be considered in such areas as an independent tool to assess regional/local geoid/quasigeoid models as well as to detect outliers among GNSS/levelling data (Godah et al, 2014a).…”

Geodesy and Cartography

“…The best performance shows the 5 th release GOCE-based GGM developed with the use of time-wise strategy. Its fit to gravity anomalies, and height anomalies in terms of the standard deviation equals 0.84 mGal and 2.8-3.4 cm, respectively (Godah et al, 2015b).…”

Accuracy assessment of high and ultra high-resolution combined GGMs, and recent satellite-only GGMs – Case studies of Poland and Ethiopia

“…Validating those combined and satellite-only GGMs in global, regional and local scales using external data such as terrestrial/airborne gravity data and geoid/quasigeoid heights from GNSS/levelling (Global Navigation Satellite System/levelling) data have been considered as a subject of investigation for the International Centre for Global Earth Models (ICGEM; Ince et al, 2019) and many other scholars (e.g. Godah and Kryński, 2013;Godah et al, 2014;Alothman et al, 2016;Odera and Fukuda, 2017;Godah et al, 2018a,b;Goyal et al, 2019;Odera, 2020;Wu et al, 2021;Yuan et al, 2022;Pham et al, 2023). Among these scholars, Yuan et al (2022) and Pham et al (2023) evaluated the Earth's gravity field up to spectral band of d/o 2190 from XGM2019e ultra high-resolution GGM.…”

“…Over this area, extended research (e.g. Krynski and Kloch, 2009;Godah and Kryński, 2013;Godah et al, 2014Godah et al, , 2018a, have been conducted to ensure the quality of satellite-only and combined GGMs for modelling the Earth's gravity field. In East Africa, the Earth's gravity field is not yet sufficiently determined, and thus, a proper evaluation of GGMs is required.…”