Optimal GPS positioning solutions interval for a crustal deformation estimation: Fid-Bau Portal

Optimal GPS positioning solutions interval for a crustal deformation estimation

Song, Dong-Seob / Yun, Hong-Sic

Abstract GPS is an essential tool in positioning which requires high precision such as velocity field estimation of tectonic plates. However it takes long time for this kind GPS solutions because of defective automatic GPS data processing system. Therefore, it is importa nt that the determination of GPS data processing interval to obtain requisite accuracy in a study of crustal deformation parameter estimation. So, the Gipsy-Oasis II software was used to estimate daily deformation of GPS stations with orbital and atmospheric parameters and least square linear fitting technique was used to estimate the velocity of the GPS stations. In this relative solution of daily positioning, the standard deviation which is scale of precision turned out better than 4mm. In this study, to determinet he optimal time-interval for a crustal deformation estimation, three kinds of time-interval was adopted, which is 2-day, 5-day and 10-day time-interval and were compared to daily solutions by the standard deviation of velocity from the calculation results. Researchresults shows that the Std of the horizontal crustal motion parameter was 1.44 times (Std=±0.66mm/yr), 2.24 times (Std=±1.03mm/yr) and 3.20 times (Std=±1.47mm/yr) worse than the Std used to obtain of the daily positioning result (Std=±0.46mm/yr). The crustal motion magnitude varied irregularly for the 2-day interval. So, we made conclusion that the 2-day interval can be applied to process GPS data for rapid velocity field estimation.