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Highlights

Recent Papers

Fournier et al. (2009): Tracking magma volume recovery at Okmok Volcano using GPS and an Unscented Kalman Filter [PDF]

Freymueller et al. (2008): Active deformation processes in Alaska, based on 15 years of GPS measurements [PDF]

Survey ties for old GPS tracking stations


This page provides a compilation of survey ties between modern and ancient GPS tracking stations. In this context, "ancient" means the early 1990s. There has been a nearly complete turnover of sites since that time, which means that it can be quite difficult to align a single solution from the old days to a modern ITRF realization. However, in many cases a site that was active at that time was eventually replaced by a current ITRF site, so a survey tie allows one to compute an accurate ITRF position for the old site.

Of course, there is also the question of the accuracy of the survey tie, but in theory these ties could be determined accurately because they require only a survey between two GPS points.

Survey ties with known values

Tie values are given as (Tied site) minus (ITRF site).

Tied site ITRF site X (m) Y (m) Z (m) σX (mm) σY (mm) σZ (mm) Source Method
KOKE (Kokee CIGNET) KOKB (Kokee IGS site) 20.140 4.625 48.806 ?? ?? ?? ?? ??
Canberra Rogue 1990-1992 Canberra TIDB 4002-S
SIO1 SIO3


Survey ties we are looking for

Tie values are given as (Tied site) minus (ITRF site).

Tied site ITRF site X (m) Y (m) Z (m) σX (mm) σY (mm) σZ (mm) Source Method
Canberra Rogue 1990-1992 Canberra TIDB 4002-S
SIO1 SIO3
XMAS (campaign site) XMIS (IGS)
Matera GIG91 site MATE or MAT1
Santiago GIG91 site SANT
WETTZELL 7598 WETTZELL 1202
O'Higgins GIG91 site OHIG
MCMU MCM4
MCM1 MCM4
Mawson GIG91 site MAW1


pre-ITRF offsets

In addition, offsets must be applied for some sites, for displacements that occurred before the earliest data used in the current ITRF (1995 or 1996). Most of these are due to earthquakes.

Site Date Event dX (mm) dY (mm) dZ (mm) σdX (mm) σdY (mm) σdZ (mm) Source
PINY/PIN1 June 1992 Landers eq
SIO3/SIO1 June 1992 Landers eq