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 |