ABSTRACT
Until the 1970s, global geoid undulations were determined based on the analysis of satellite orbital perturbations in conjunction with surface gravity measurements. The radar altimeter mounted on the artificial satellite is an instrument that can map the ocean surface and give information about the gravitational field of Earth. Comparison between the altimetric and gravimetric geoids shows constant offsets and tilts due to inaccuracies in data collection and numerical calculations in both methods. The gravity measurements utilized to construct the free-air gravity contour map were referred to the International Gravity Formula 1930. The ocean basins surrounding the Mid-Atlantic Ridge are characterized by negative geoid values. M. Talwani and X. Le Pichon noted an apparent strong correspondence between topography and regional gravity in the North Atlantic Ocean. The Puerto Rico Trench is characterized by arcuate geoid lows which is the most negative one in the North Atlantic Ocean.
