Fig. 1

Outlier removal process for the north component of three baselines as labeled. Right panels show closer look of fluctuation of baselines shown at left of each panel. Red dots indicate outputs of kinematic analysis of TRACK. Green dots indicate coordinates after removing epochs with large post-fit residuals of double difference (DD) and/or determined from small number of DDs (Additional file 1: Fig. S2; see section "Postprocessing to remove outliers"). Blue dots indicate coordinates with 30-s intervals after the interpolation of neighboring epochs for outliers removed from the green dots with the whole-year and the local standard deviation criteria (see section "Postprocessing to remove outliers"). The same plots but for the east and up components are provided in Additional file 1: Fig. S1