Nigeria does not have an officially accepted geoid model. Various efforts are made to improve the country’s gravimetric data base, and for the coastal regions the use of modern satellite-altimetric data bases derived from Cryosat-2 and Sentinel-3 appears promising. In this work, we ask whether these new data sets are consistent with ship-borne gravity. Along the Gulf of Guinea, the BGI archive provides indeed marine gravity data, but they originate from different instruments onboard various cruises between 1970-1974, and they are not well documented. We show that with adopting some plausible assumptions from literature research, it is possible to apply cross-over adjustment to the historical BGI data, and the final RMSD compared to modern satellite data sets amounts to only 3-4 mGal.

Michael Bako (1,2) and Jürgen Kusche (2)

(1) Federal University of Technology, Minna, Nigeria (2) University of Bonn, Germany