Vertical velocities table
The NGL08_Vertical-Velocities_Table provides the vertical GPS velocities and uncertainties from the 818 stations fulfilling the criteria of 3 years of minimum length and data gaps not exceeding 30%, estimated by the NGL group using MIDAS (Blewitt et al. 2016).
Daily time series
The NGL08.zip file contains individual station data files of daily position time series in ITRF2008 with respect to the position at the mid time series epoch. These positions are expressed in meters in the local frame (North, East, and Up). The reference position and the 3D velocity (obtained using MIDAS) in the local coordinate system (East, North, Up) are provided in the header of each file.
The NGL08_discontinuities_Table.txt file provides the position offsets that can affect the station position and velocity estimates, as indicated by the NGL group. Note that MIDAS should be robust regarding the velocity estimates in presence of offsets, but not the parametric methods (e.g. least squares adjustment).
More downloads and information can be found at the Nevada Geodetic Laboratory website.