My research interests involve using high-precision Global Navigation Satellite System (GNSS) measurements based on geodesy to study active deformation and improve our understanding of the earthquake fault system. The objective is to understand the dynamic processes of Earth's crust, which have critical implications for earthquake hazard assessment and tectonic studies. Dislocation and strain modeling are conducted to model the causative fault(s) that could have produced observed three-dimensional velocities and displacements of GNSS stations by using the MATLAB computational package. Elevation-related and gravity modeling has been carried out to study the different uplift rates because of neotectonic faults and lineaments that pass through the region and enhance the incision of the channel. GNSS reflectometry technique with tide gauge is applied to monitor the land and sea-level vertical records at coastal areas. Multi-constellation systems signals are studied for comparative analysis such as precise point positioning and multipath error analysis. The study is also concerned with the ionosphere and troposphere error model by using the delay in GNSS signals.