Implementation of a rigorous least-squares modification of Stokes formula to compute a gravimetric geoid model over Saudi Arabia (SAGEO13)

Abstract

A precise gravimetric geoid model (SAGEO13) is computed for the Kingdom of Saudi Arabia using a rigorous stochastic computational method. The computational methodology is based on a combination of least-squares (LS) modification of Stokes formula and the additive corrections for topographic, ellipsoidal, atmospheric and downward continuation effects on the geoid solution. In this study, we used the terrestrial gravity data, digital elevation model (SRTM3) and seven geopotential models (GGMs) to compute the a new geoid model for Saudi Arabia. The least-squares coefficients are derived based on the optimisation of the input modification parameters. The gravimetric solution and its additive corrections are computed based on the optimum LS coefficients. Comparing to GPS-levelling data, SAGEO13 shows a fit of 18 cm (RMS) after using the 4-parameter fitting model.