Zero-Tide System

The zero-tide system is a conventional tide system in which the permanent (time-averaged) part of the direct tidal potential caused by the Moon and the Sun is removed, while the indirect deformation effects of the Earth remain included.

In geodesy, the zero-tide system is the standard convention used for the realization of the International Terrestrial Reference Frame (ITRF). GNSS station coordinates and many geodetic products are provided in the zero-tide system to ensure global consistency. The choice of tide system affects station coordinates at the millimeter level and must be clearly specified in precise geodetic applications.