Since 2010, a slew of new satellite altimetry missions has started providing gravity data generated from
altimetry with worldwide coverage and high quality that rivals shipborne gravity measurements in several areas. As a result, worldwide offshore high-resolution gravity fields have considerably improved. This
paper aims to compare two altimetry gravity models i.e. DTU21 and SSv29.1 with shipborne gravity measurements to evaluate their accuracies over the Red Sea. At first, the DTU21 and SSv29.1 altimetry models
were compared with the shipborne data at different water depths to evaluate the impact of bathymetry
depths on the accuracy. The corresponding results revealed that the DTU21 gravity model gave the best
results in the comparison of all shipborne with a standard deviation (s.d.) of 7.37 mGal and a Root Mean
Square (RMS) of 8.73 mGal, while the SSv29.1 model achieve an s.d. of 8.50 mGal and an RMS of 8.81
mGal. In water depths less than 1000 m the DTU21 model gives the best results in terms of s.d. and
RMS, while the SSv29.1 model achieves better results at water depths ranging between 1000 m and
3000 m |