Development of a local geoid model for the Dnister PSPP territory (Ukraine)

The Dnister Pumped Storage Power Plant (PSPP) is subject to significant natural and anthropogenic loads, requiring millimeter-level precision in determining vertical displacements. The purpose of this study is to develop a local geometric geoid model to establish a high-precision vertical datum for satellite geodetic monitoring. The input data were derived from high-precision geometric leveling and Global Navigation Satellite System (GNSS) measurements conducted in 2022. Modeling was performed using the least-squares collocation method within the Remove-Compute-Restore Procedure, using the EGM2008 global geopotential model and Legendre functions of non-integer degree. The model was computed on a regular 8″ × 8″ grid. The resulting local geoid model has a standard deviation of 3.4 mm relative to the GNSS leveling data. Spatially, a 60–80 mm increase in geoid height from east to west is observed, with a sharp gradient in the Dnister River right-bank zone, consistent with the terrain morphology. No systematic trends were detected in the residuals. The developed model enables conversion of ellipsoidal heights to normal heights with millimeter-level accuracy over an area of approximately 10 km 2 , providing a reliable basis for real-time GNSS monitoring of vertical deformations of hydraulic structures in both static and kinematic modes.