The first step of ITRF2005 strategy is the independent computation of a long-term stacked Terrestrial Reference Frame (TRF) for each measurement technique under the assumption of linear motions. The associated EOPs are readjusted at the same time to make them consistent with their stacked TRFs. A break-wise approach is used to take into account discontinuities in the time series coming from any physical motion of the ground caused by an earthquake or a change in equipment.

The residuals of these computations, based on the standard relationship linking 2 frames, represent the non-linear part of point behaviors with respect to the secular frame. They can consequently be interpreted as point motions viewed by space geodesy.

Plots of residual time series are available online. Station position residual times series can be displayed as they are, or with their piecewise linear trend.

IGS (GPS)

ILRS (SLR)

IVS (VLBI)

IDS (DORIS). IGN LCA

• yyyy.yyyyy : epoch in decimal year.
• res : residual value in millimeter in North , East and Up component depending on the file extension (*.DN)(*.DE) and (*.DH) respectively.
• sigma: 1-sigma formal error.
• soln : solution number (see the discontinuity file).