Detection of Tidal Loading Signals from GPS Permanent Array of GSI Japan

Abstract

The tidal displacement signals are derived for the Japan area from the GPS Earth Observation Network (GEONET) of Geographical Survey Institute. The amplitude of these tidal signals is up to 2.5 cm and most of them are explained by the ocean tide loading displacement model by Matsumoto et al. (2000, 2001). The loading tide signals affect the troposphere delay estimates by more than 1 cm in southwestern Japan if they are not corrected. These tidal signals in the displacement and troposphere estimates are effectively eliminated by applying the ocean tide loading correction with the model for most of the major tidal constituents. The comparison of residual tidal signals by applying the two ocean loading models shows reduction of the residual M2 tidal signals by applying the correction with the newer model. These results demonstrate the capability of a dense GPS network to detect un-modeled tidal signals.