Multi-epoch GNSS Data Analysis on Geodynamics Study of Central Java

Geometrics method based on multi-epoch GNNS data is one of the methods used in the geodynamic study. Three epochs of GNNS measurement at some benchmarks are used to measure general feature of the geodynamic of Java Island in 3 Dimensions. The coordinate solutions have been determined using simultaneous network adjustment connected to the global network available around Indonesia; those are: COCO, BAN2, PIMO, DGAR, NTUS and DARW. The processing of three days GNNS (Rinex) data have been done through a daily processing using GAMIT and a combination processing using GLOBK. The output of the computation shows that the precision of the baseline ranges from 1 – 5mm, while the precision of the daily and the combination estimated coordinate ranges from 1 to 6mm. Based on the coordinate difference, the surface velocity of the site is ranged from 0.6 to 7.3mm/year, with the direction of the movement to the eastward. In general, the precision of the Y coordinate components, which represents the height components in the Indonesia area, is always lower than the X and Z components.