This report outlines the high precision level survey completed between the SEAFRAME tide gauge and continuous GPS station in Apia, Western Samoa from 18 - 30 May 2010.

This report outlines the level survey completed during the visit to Pohnpei, Federated States of Micronesia (FSM) from 20 February - 4 March 2011.

This report outlines the high precision level survey completed between the SEAFRAME tide gauge and continuous GPS station in Nuku-alofa, Tonga from 18 - 26 April 2010.

This document overviews the data analysis of the VICSZ GNSS 2011 campaign, and presents the results including the repeatability RMS (root mean square) of the station coordinates, and the final computed station coordinates. The average of the repeatability RMS of the station coordinates are 1.4 mm, 1.8 mm and 4.3 mm for the northing, easting and height components, respectively.

An application dated 12 December 2011 for verification of a reference standard of measurement under Regulation 12 of the National Measurement Regulations 1999 was received from the Position Partners PTY LTD for verification of GDA94 position on their owned or managed station monuments. This report documents the processing and analysis of GPS data observed by the Position Partners PTY LTD during a 7-day period from 20 to 26 November 2011 (day of year 324 to 330) for three stations (5KAD, 5LON and 5REG) to satisfy the position verification requirements.

An application dated 01 November 2012 for verification of a reference standard of measurement under Regulation 12 of the National Measurement Regulations 1999 was received from the Clermont Coal Mine of the Rio Tinto Coal Australia (RTCA) for verification of GDA94 position on their owned or managed station monument. This report documents the processing and analysis of GPS data observed by the Clermont Coal Mine during a 7-day period from 28 October to 03 November 2012 (day of year 302 to 308) for the station CCMB to satisfy the position verification requirements.

Australia, like most developed countries, is constantly driven by the need for improved accuracy, stability, and reliability of its geodetic products. These products underpin a variety of science endeavours, as well as an explosion of precise positioning applications for industrial and societal use. It is well understood that the strength of the Global Geodetic Observing System is obtained in two ways. The first is the continued refinement of the individual geodetic techniques (VLBI, SLR, GNSS etc); and the second is the improvement of the connection between those techniques at co-located sites, of which Australia now has five (Yarragadee, Mt Stromlo, Katherine, Hobart and Parkes). This presentation will explore efforts in Australia towards improving both of these elements. A comparison of local tie results to ITRF2008 will be given for Yarragadee in Western Australia. The residual error is comprised of around 10mm in GPS systematic error caused by the un-calibrated Antenna / Radome combination, several millimetres of survey error including site deformation, and up to 5mm combination technique error.

Geoscience Australia has recently conducted absolute gravity observations at Davis and Mawson stations in the Australian Antarctic Territory to establish accurate gravity reference points for past and future gravity surveys. These absolute gravity observations are the first such measurements undertaken at any of the Australian Antarctic stations and will not only provide an accurate absolute datum for future gravity work but will also enable gravity surveys that have already been conducted in the Australian Antarctic Territory to be tied to the same datum, thus allowing past and future gravity surveys to be accurately merged and combined.

The Mw=7.8 earthquake of 15 July, 2009 occurred along a section of the subduction zone south of New Zealand, where the Puysegur Block subducts beneath the Pacific Plate. The orientation of this subduction zone suggests that tsunamis generated along it pose a significant threat to the southeast coast of Australia, but since it had not experienced megathrust rupture until the 15 July event, the question of whether it was accumulating strain energy whose release could result in a large tsunami was open. We have used seismic, tsunami, geodetic and SAR data to study this earthquake and find that it involved primarily thrust motion on a fault plane dipping east at a shallow angle, consistent with expectations for a megathrust earthquake. The ability to use multiple data types to study this earthquake lead to improved ability to resolve parameters such as rupture velocity that are often difficult to constrain with seismic data alone. Seismic array data agree with rupture modelling of broadband waveforms in their prediction of a bilateral component to the earthquake rupture. Also, a tsunami of about 10 cm peak-to-peak amplitude was recorded by two tsunameter buoys in the Tasman Sea west of the epicenter, and we find that the tsunami travel times indicated by these data suggest the earthquake was characterised by a low rupture velocity of around 1 km/s. We will also present comparisons against GPS and InSAR data that further constrain parameters of the rupture. Finally, we will discuss the potential for earthquake activity further south along the Puysegur Trench, which poses a tsunami threat particularly to the eastern coast of Tasmania.

The centrifugial acceleration of the Solar system, resulting from the gravitational attraction of the Galaxy centre, causes a phenomenon known as 'secular aberrration drift'. This acceleration of the Solar system barycentre has been ignored so far in the standard procedures for high-precision astrometry. It turns out that the current definition of the celestial reference frame as epochless and based on the assumption that quasars have no detectable proper motions, needs to be revised. In the future, a realization of the celestial reference system (realized either with VLBI, or GAIA) should correct source coordinates from this effect, possibly by providing source positions together with their proper motions. Alternatively, the galactocentric acceleration may be incorporated into the conventional group delay model applied for VLBI data analysis.