In the current study, the global geopotential harmonic models are used to densify gravity values
along precise leveling routes, and hence to minimize the discretization error in computing the
orthometric correction and to represent an economical alternative. Furthermore, these models are
checked regarding their capability of being the only source of gravity information along spirit
leveling lines. The orthometric corrections, computed for two simulated test links, are compared
with those resulting from using purely observed gravity.

Based on the obtained results, it is
recommended to use the geopotential harmonic models as an economical source of gravity
information along precise levelling routes. Moreover, it is recommended to investigate the
application of the remove-restore technique of geopotential models in the computation of
orthometric correction.