Local Tie Record 2007/19 Summary

The integrity and strengths of multi-technique terrestrial reference frames such as ITRF2005 depend on the precisely measured and expressed local tie connections between space geodetic observing systems at co-located observatories.

A local tie survey was conducted at the Yarragadee (Moblas 5) Satellite Laser Ranging (SLR) observatory, on the Yatharagga property in Western Australia, in May/June of 2007. The aim of the survey was to precisely measure the local terrestrial connections between the space-based geodetic observing systems co-located at the observatory, which include GPS, GLONASS, SLR and DORIS.

In particular, this record documents the indirect determination of the SLR invariant reference point (IVP). Geoscience Australia has routinely performed classical terrestrial surveys at the Moblas 5 SLR observatory, including surveys in 1992, 1999, 2001 and 2003. Precise survey observations were made between the permanent survey monuments surrounding the SLR observatory to monitor their stability as part of a consistent, stable terrestrial network from which local tie connections were made to the SLR IVP and other observing systems. The relationship between points of interest included the millimetre level accurate connections and their associated variance covariance matrix, providing an un-broken contribution of the Yarragadee (Moblas 5) observatory to future terrestrial reference frames and other scientific outputs. In this report, observational and analysis techniques are reviewed and results are given. In particular, the 2007 survey results are compared with those obtained at Yarragadee in 2003.

• See the complete Record 2007/19 [PDF_2.45Mb]

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