A new approach for the determination of the gravitational gradient tensor using the observations from satellite altimetry, Case Study: Persian Gulf

With the appearance of the satellite altimetry in 1973, a new window was opened in the oceanography, marine sciences and Earth-related studies. Advances in the sensors technology and different satellite altimetry missions in the recent years led to a great evolution in geodesy and the gravity field modeling studies. Satellite altimetry provides a huge source of information for the geoid determination with high accuracy and spatial resolution. The information from this approach is a sufficient alternate for the marine gravity data in the highfrequency modeling of the Earth’s gravity field in marine areas. Marine gravity observations always carry a high noise level due to the environmental effects. Moreover, it is not possible to model the high frequencies of the Earth’s gravity field in a global scale using these observations. The gravitational gradient tensor, as the second order spatial derivatives of the gravitational potential, provides more information than other measurements from the Earth’s gravity field such as the gravity anomaly. In this paper, a new approach is introduced for the determination of the gravitational gradient tensor at sea level based on the satellite altimetry and using two modeling techniques, namely radial base functions and harmonic splines. As a case study, the gravitational gradient tensor is determined in Persian Gulf based on the satellite altimetry data, and the results are presented. By the investigation of the results for the gravitational gradient tensor, it is concluded that modeling of the Earth’s gravity field using radial base functions leads to better results compared to the modeling based on the harmonic splines.