NORMAL HEIGHT DETERMINATION FROM DIFFERENT METHODOLOGIES

The determination of normal height is essential for scientific and engineering applications, and it is intrinsically linked to the Earth’s gravity potential. This study compares two methodologies for computing normal heights following the International Height Reference System (IHRS) conventions. The first strategy estimates gravity potential via a geoid model derived from Least Squares Collocation (LSC) with gridded data; the second determines the disturbing potential through Numerical Integration (NI) using a modified Hotine integral and non-gridded data. A total of 112 benchmarks from the High Precision Altimetric Network (RAAP) in the Brazilian states of São Paulo and Minas Gerais were used for comparison. Results show a mean difference of -0.05 m between the LSC and NI methods and 0.60 m when compared with the official RAAP values. The findings suggest that both methods are consistent, particularly in regions with smooth gravity disturbance patterns, although discrepancies increase in areas with poor gravity data coverage. These outcomes support the applicability of the proposed methods in heterogeneous geodetic infrastructures, especially in developing countries.