Performance Evaluation of Satellite Gravity on Variable Test Points and Geophysical Models in Gongola Basin, Nigeria

Abstract

The recent advent of new satellite missions provides models of gravity data with high quality and global coverage that is on par with conventional gravity measurements. A drawback is the myriad of models to choose from and the number of test points to use for validation.  As a result, an accuracy assessment needs to be performed to isolate the best model. Therefore, this paper compared 21 satellite models at varying testing points. Furthermore, the best gravity model was assessed based on 2-D (Two-Dimensional) geophysical modeling constrained by the aeromagnetic survey. XGM2019e_2159 gravity model attained the highest performance indicator value from the quantitative analysis of the Gongola Basin. It has an RMSE (0.847861), MAE (4.102917), RMSPE (14.24%), MAPE (12.24%) and highest correlation (0.847861) with the terrestrial Bouguer anomalies, for this reason, it is deemed most suitable for the application of this research. Overall, based on the mean accuracy of the whole set of points, the best six (6) satellite models in decreasing accuracy are XGM2019e-2159, XGM2016, GECO, EGM-2008, EIGEN-6C4 and GGM05C. Generally, a set of data points might perform better than another set, one should use as much available data set for selecting the best model ensuring the data sets are well distributed across the research area. The satellite data performed slightly better than the terrestrial data based on the geophysical modeling by a discrepancy of ±2 mGal. Generally, a set of data points might perform better than another set, therefore one should use as much available data set for selecting the best model ensuring the data sets are well distributed across the research area.