Globally, research studies revealed that the sea level is rising in the last decade, with different rates for different regions of the Earth. Nationally, the issue of re-defining the Egyptian vertical geodetic datum and the existing problem of sea level rising has attained a great attention in the geodetic community.
In 2001, the Survey Research Institute (SRI) of the National Water Research Center (NWRC) has installed a stat-of-the-art sea level observing system at Alexandria. The new installed system consists of three devices integrated together in a unified scheme: a tide gauge, a meteorological unit, and a satellite-based GPS geodetic receiver.
Analyzing the GPS continuous time series and estimating the rate of ground deformation at the tide gauge station's site is an important issue to obtain absolute rate of MSL rise. Hence, this research concentrates on estimating the absolute rate of MSL rise at Alexandria tide gauge station using continuous tide and GPS observations.