Abstract In this paper a approach to determining heights above sealevel ——GPS gravity-potential leveling is proposed. Its principle, algorithm and error sources are addressed, and the results of experiments with this approach using GPS leveling data and geopotential model EIGENCG03 are presented. It is shown that the accuracy of height above sealevel has been attainable at 0.5 m level and that the accuracy of height difference above sealevel has been achievable to be better than 10 cm over a distance up to several tens of kilometers. The geopotential model error is proofed to be the major error source of the height determination; the error in geodetic height differences measured by GPS is the limitation to the accuracy of the height difference above sealevel over a short distance. The gravity-potential leveling is expected to be helpful to the height modernization.
