Ongoing developments in geodetic positioning towards greater accuracies with lower latency are now allowing the measurement of the dynamics of the Earth's crust in near real time. However, in the Australian circumstance a sparsity of geodetic infrastructure has limited the application of modern, geodetic science to broader geoscience research programs. Recent enhancements to the Australian geodetic infrastructure, through the AuScope initiative, offer opportunities for research into refinement of geodetic accuracies, as well as their application to measuring crustal deformation.

This report refers to the 5th Local Monitoring Survey completed at the Pohnpei (POHN) continuous GPS (CGPS) station on Saturday 15 August 2009

The new Australian geodetic VLBI network operated by University of Tasmania (UTAS) started regular observations in October, 2010. Three 12-meter "Patriot" radio telescopes are focused on improvement of the celestial and terrestrial reference frames in the southern hemisphere. We present first results from analysis of an eight-month set of geodetic VLBI data.

Recognising the importance of improving the regional geodetic framework in the Asia-Pacific region, the Asia-Pacific Reference Frame (APREF) project call for participation was released in March 2010. The APREF project is a joint initiative of the Permanent Committee for GIS Infrastructure of the Asia-Pacific (PCGIAP) and the International Association of Geodesy (IAG). Currently, GNSS data from a Continuously Operating Reference Station (CORS) network of approximately 290 stations, contributed by 28 countries, is now available and processed by three Analysis Centres (ACs). The contributions of the ACs are combined into a weekly solution in SINEX format using the CATREF software. Three kinds of APREF products are available, rapid daily solutions which are produced using IGS rapid products, final daily solutions which are produced using IGS final products, and the weekly combined solutions. The core product of the APREF is the weekly solution; it provides a reliable time-series of the regional reference frame in the International Terrestrial Reference Frame (ITRF) and a quality assessment of the performance of participating Asia-Pacific GNSS CORS stations. In this presentation, we update the progress of the APREF project and perspectives towards a regional focus for cooperation in the definition, realisation and densification of the ITRF in the Asia-Pacific.

The Asia-Pacific Reference Frame (APREF) Project is a regional initiative that seeks to improve the geodetic infrastructure of the Asia-Pacific region. As a joint effort of the Permanent Committee on GIS Infrastructure for Asia and the Pacific (PCGIAP) and the International Association of Geodesy (IAG), APREF is developing a start-of-the-art regional geodetic reference frame. In the Asia-Pacific region there are a substantial number of state-of-the-art GNSS networks, which are commonly operated by national mapping agencies or private sector organisations. These networks represent an important and significant investment by the respective governments and industry in their own spatial infrastructure. In the APREF initiative these networks are combined to realize a high-standard regional reference frame. The GNSS data of the network is processed by different Analysis Centres (ACs). The contributions of the different ACs are combined into a weekly solution by the APREF Central Bureau. This weekly solution is the core product of the APREF; it contains weekly estimates of the coordinates of the participating Asia-Pacific GNSS tracking stations and their covariance information. The APREF product, which is available since the first quarter of 2010, gives a reliable time-series of a regional reference frame in the International Terrestrial Reference Frame and a quality assessment of the performance of the GNSS CORS stations included in the network. This contribution gives an overview of the current status of the APREF network and an analysis of the first APREF products

This report gives an overview of the activities of the Geoscience Australia IVS Analysis Center during 2011.

A centralised metadata store is fundamental for the efficient management and operation of GNSS networks. The metadata store should be accessible, reliable, accurate, and form a single-point-of-truth containing metadata for hundreds of stations. This paper presents an outline of Geoscience Australia's Oracle based centralised metadata management system for maintaining station metadata for GNSS networks operating at state-wide, to national and regional levels. The benefits of the system in supporting several key GNSS operations such as monitoring data quality, generating IGS formatted station log files, validating RINEX header files and generating summary files in customary formats is demonstrated. This paper also discusses the system architecture for maintaining station metadata through manual data entry by Geoscience Australia operators and authorised state users responsible for designated stations or networks. Processes for automatic metadata maintenance for core IGS stations used in routine data analysis are also summarised.

Ongoing developments in geodetic positioning towards greater accuracies with lower latency are now allowing the measurement of the dynamics of the Earth's crust in near real time. However, in the Australian circumstance a sparsity of geodetic infrastructure has limited the application of modern, geodetic science to broader geoscience research programs. Recent enhancements to the Australian geodetic infrastructure, through the AuScope initiative, offer opportunities for research into refinement of geodetic accuracies, as well as their application to measuring crustal deformation.

The annual Asia Pacific Regional Geodetic Project (APRGP) GPS campaigns are an important activity of the regional geodesy working group of the Permanent Committee on GIS Infrastructure for Asia and the Pacific Region (PCGIAP). The major objective of these campaigns is the densification of the International Terrestrial Reference Frame (ITRF) in the Asia-Pacific region. The APRGP GPS campaigns consist of 7-day observation sessions and have been undertaken from 1997 to 2008. In this work, we focus on the assessment of realistic uncertainty estimates of the derived crustal velocities, which is still an important unresolved issue. Although assessments of the quality of Continuous GPS (CGPS) determinations of crustal velocity have previously been undertaken, little research has been conducted on the quality of the velocity estimates derived from campaign-based coordinate time series. We have compared our velocity estimates with those published by the International GNSS service (IGS) at common sites and found that they are consistent at 1.4, 1.7, 3.9 mm/yr level in the east, north and up components, respectively. Also, we find that a minimum of 3 years of campaign data is required before reliable velocity estimates can be derived from campaign-based GPS, which is mostly due to the increased possibility of outliers.

Australia's National Geospatial Reference System (NGRS) is a continually evolving system of infrastructure, data, software and knowledge. The NGRS serves the broader community by providing an accurate foundation for positioning, and consequently all spatial data. The NGRS is administered by the Intergovernmental Committee on Surveying and Mapping (ICSM) and maintained by its Federal and State jurisdictions. Increasingly, the role of Global Navigation Satellite Systems (GNSS) in positioning has required the globalisation of national coordinate systems. In the early 1990's ICSM endorsed the adoption of the Geocentric Datum of Australia (GDA94) which was aligned to the International Terrestrial Reference Frame (ITRF) with a stated uncertainty of 30mm horizontally and 50mm vertically. Since that time crustal deformation and the demand for higher accuracies has resulted in GDA94 no longer adequately serving user requirements. ITRF has continued to evolve in accuracy and distribution to the extent that it now requires very accurate modelling of linear and non-linear crustal deformation. Even the Australia plate, which has long been considered to be rigid, is now considered to be deforming at levels detectable by modern geodesy. Consequently, infrastructure development programs such as AuScope have been implemented to ensure that crustal deformation can be better measured. The Auscope program also aims to improve the accuracy of the ITRF by contributing to the next generation of the Global Geodetic Observing System in our region. This approach will ensure that the ITRF continues to evolve and that Australia's NGRS is integrally connected to it with equivalent accuracies. Ultimately this will remove the need for National Reference Systems, with a globally homogenous and stable reference system (e.g., ITRF) being far more beneficial to society. This paper reviews Australia's contribution to GGOS and how this impacts on positioning in Australia.