INVESTIGATION OF LSMSA APPROACH IN LOCAL GEOID MODELING

This article presents the results of creating a gravimetric geoid model using a modified Stokes formula, implemented via the method of least squares with additive correction (LSMSA). Typically, the computation of geoid height is based on gravity measurements at points on or above the Earth’s surface. However, practical limitations often restrict available gravity data to a spherical cap, leading to truncation errors. To mitigate these errors, it is essential to integrate terrestrial data with a global geopotential model (GGM). For an optimal gravimetric geoid definition, the GGM must be selected to best match the local gravity field. This selection is accomplished by comparing geodetic quantities derived from the GGM - such as potential, geoid heights, deflection of the vertical, gravity, and anomaly values - with those obtained from GNSS/levelling and terrestrial gravity measurements. This comparison reduces the impact of assumptions and approximations inherent in the Stokes method, thereby enhancing the accuracy of geoid height determination. To develop a local geoid using heterogeneous data sources (including gravity anomalies, digital high relief models, global geopotential models, and GNSS/levelling data) Least squares modification of Stokes formula with additive correction (LSMSA) method was chosen. This method is one of the simplest and most practical approaches, which has been successfully employed in regional geoid modelling. The LSMSA approach facilitates optimal integration of terrestrial and global data, contributing to more accurate and reliable geoid modelling.