International Service for the Geoid


Search in ISG Website




CoverNewton's Bulletin

Issue n. 5, June 2015 - Assessment of GOCE Geopotential Models    [pp. 149-162]

Validation of GOCE Models in Africa

Hussein A. Abd-Elmotaal

Download file


In modern geodesy, the geoid computation is carried out using the so-called remove-restore technique. In this technique, the effect of the topography and its isostatic compensation as well as the effect of a global reference field are removed from the gravimetric quantities being used in the geoid computation. The quality of the reference geopotential model used in the framework of the remove-restore technique plays a great role in estimating the accuracy of the computed geoid. In the last decade, the GOCE gravity field dedicated satellite mission has taken place in order to enhance the gravity field recovery worldwide. Numerous GOCE geopotential models have already been released. Each geopotential model depends on the strategy of the solution and the inclusion of terrestrial gravity data. The main aim of this paper is to validate the recently released GOCE geopotential models in Africa. The results show that the EIGEN-6C4 and GO CONS GCF 2 DIR R5 models give the smallest standard deviation and range of the reduced isostatic anomalies, respectively. However, the range and the standard deviation of the reduced isostatic anomalies are relatively too high, which shows that none of the GOCE released geopotential models ideally fits the African gravity field.