Analysis of GOCE-based Global Geopotential Models and their use for modelling gravity field - A case study of Poland

The GOCE (Gravity field and Ocean Circulation Explorer) satellite gravimetry mission was launched on March 17th, 2009 by the European Space Agency (ESA) and and re-entered the Earth’s atmosphere on November 11th, 2013. The data obtained from GOCE mission have remarkably improved the modelling of the Earth gravity field. Several global geopotential models (GGMs) based on GOCE satellite mission data have been developed and released for the scientific use by ESA and other institutions. In this paper the accuracy of the 1st – 5th release GOCE-based GGMs as well as the recent high resolution combined GGM, i.e. EIGEN solution, has been analysed over the area of Poland.
Free-air gravity anomalies and height anomalies determined from GOCE-based GGMs have been compared with the corresponding ones obtained from the EGM08. They have also been compared with the corresponding ones obtained from absolute gravity data using the spectral enhancement method (SEM). Moreover, height anomalies determined from GOCE-based GGMs were compared with the corresponding ones obtained from different GNSS/levelling data sets with the use of the SEM. The results of the comparison reveal gradual improvement from the 1st to the 5th release of GOCE-based GGMs investigated. The fit of the abovementioned gravity functionals, i.e. gravity anomalies and height anomalies, obtained from GOCE-based GGMs to the respective ones obtained from ground truth data has been discussed.

Keywords. GOCE, global geopotential model, free-air gravity anomaly, height anomaly, GNSS/levelling