Sensitivity of Double-Difference and Precise Point Positioning GNSS Processing Strategies to Determine Ocean Tidal Loading Effect in a Large and Closed Basin Environment
摘要
Ocean tidal loading (OTL) induced surface displacements, driven by lunar and solar gravitational forces, present significant challenges in geodetic applications, requiring precise modeling to improve GNSS positioning accuracy. The study conducts a methodological and feasibility assessment of the differential and absolute approaches for detecting and quantifying OTL signals from GNSS coordinate time series. By analyzing GNSS data from selected stations, this research assesses the strengths and limitations of DD and PPP in estimating OTL displacements. Applying the OTL model correction reduced coordinate RMS values by up to 22% in the vertical and 10–15% in the horizontal components, confirming the model’s effectiveness in reproducing dominant tidal displacements. The largest residual after applying the OTL model appears in the PPP-derived vertical component for