Geoid modeling with least squares modification of Hotine’s integral using gravity disturbances in Turkey

This study aims to investigate the regional gravimetric geoid modeling accuracy performance using least squares modification of Hotine’s integral with additive corrections (LSMHA) method in Turkey. The gravimetric geoid model is computed using 1' × 1' resolution gravity disturbances calculated from the complete Bouguer anomaly grid. It is validated in absolute and relative manners using the countrywide and locally distributed precise GNSS/leveling dataset having 100 and 301 benchmarks, respectively. The validation statistics are generated before and after removing the systematic differences between the geoid model and the local vertical datum. The obtained accuracy of the calculated geoid model with LSMHA is compared with the best-fitting geoid model computed via commonly used least squares modification of Stokes’s integral (LSMSA) method. The results reveal that the accuracy of the Hotine’s solution is 8.8 cm, compared to the 8.6 cm achieved from the Stokes counterpart in the whole country. Based on the local assessment in the western part of Turkey, the models show much better fitting performance at the local 301 GNSS/leveling benchmarks than the countrywide validation results. The accuracies of the Hotine’s and Stokes’s solutions at the local GNSS/leveling dataset are 4.4 and 4.3 cm, respectively. As a result, it is revealed that the LSMHA method using gravity disturbance gives a competitive result to the LSMSA method in regional gravimetric geoid modeling.