Presented by: Leila Hernandez Dennis Manglicmot GMAT 9205 Fundamentals of Geo-positioning

Continuously Operating Reference System (CORS) Permanent base stations that are used to continuously observe and measure using Global Navigation Satellite System (GNSS) provide real time accurate positioning Incorporated into networks to reduce errors and to have a capability to deliver positioning services for a state, a country or world-wide Used as part of the realization of the State Datums

Agriculture Mining Construction Scientific Surveying Navigation Mapping CORS Application

Some of the CORS Networks in Australia AFN ARGN GPSnetwork Perth South Australia CORS network SmartNet Aus SunPOZ VICmap POS GPSNet™ CORSnet NSW

CORS: Australia Australian Fiducial Network (AFN) comprises of 8 stations within mainland Australia (including Tasmania) Connects to ITRF Australian Regional GPS Network (ARGN) – combination of the AFN and 8 other stations beyond the mainland Australia

GPSnetwork Perth Uses Virtual Reference Stations (VRS) to eliminate potential systematic errors World’s first privately owned and operated VRS network which supports GNSS capabilities

South Australian CORS Network Metro Network – 8 operating stations with 2cm accuracy using NRTK within 80km of Adelaide CBD SA Statewide Network

SmartNet Aus Utilises Leica Geosystems’ Spider software to create RTK corrections in various formats Available in South Australia and in Gold Coast, QLD

SunPOZ Covers south-east corner of Queensland Uses Trimble’s VRS™ technology

VicMap Position - GPSnet™ Private and public stakeholders More than 100 stations Accuracy: ±2cm within 25km of CORS

Number of stations May 2011: 61 Future: 120 Data Services DGPS RTK RINEX CORSnet-NSW

Additional Information VicMap POS GPSNet™ is currently the largest CORS network in Australia In Perth and South Australia, reference stations are managed by private companies Data accessibility can sometimes be an issue

CORS and Reference Datum WGS84 recalculated every few years for GPS control GDA94 based on ITRF92 but is fixed on a number of reference points in Australia compatible with modern positioning techniques e.g. GPS

Concerns Surveyors and spatial professionals represents only a small minority of future CORS users in Australia. ITRF is realised every 3 or so years and Australian Datum is realised every 30 years or so Plate tectonic movement of 7cm per year NNE direction

Concerns (cont’d) The need to have modern GNSS positioning techniques and surveying techniques and to ensure they are accurate, reliable and easy to use Interoperability with other state’s CORS networks Compatibility of AUSPOS Legal Traceability

Significant distortions in the GDA94 (1997) for NSW

Solution: GDA94 (2010) Defined to improve shortcomings of the initial datum definition and reduce distortion 3-dimensional coordinate system Provides direct connection to the Australian Fiducial Network (AFN) and Australian Regional GNSS Network (ARGN) Potential sources of error eliminated Distortion-free spatial control across the network Improved positioning framework Regulation 13 certificates

Global GDA implementation CORS networks using ‘global’ GDA VicMap POS GPSnet™ SmartNet Aus CORSnet NSW SunPOZ

A few things to note: Complete re-adjustment of geodetic ground control networks in NSW will be done after GDA2015 is implemented. Site calibration will continue to be essential GNSS survey practice in NSW to relate the two realisations of GDA94 to each other. However, site calibration is essential only for applications that needs to be tied to existing ground control network

References: GPS Network Perth 2011, GPS Network Perth, viewed 29 May 2011,. Haasdyk, J 2009, “Automatic Bernese Processing of CORSnet- NSW GPS data for deformation monitoring”, Engineering thesis, University of New South Wales Janssen, V & McElroy, S 2011, “Coordinates and CORSnet-NSW: Dealing with distortions in GDA94”, Position, no. 50, pp Janssen, V and White, A and Yan, T (2010) CORSnet-NSW: Towards state-wide CORS infrastructure for New South Wales, Australia. In: Proceedings of XXIV FIG International Congress, April 2010, Sydney, Australia.

References (cont’d): NSW Land and Property Management Authority c 2011, CORSnet-NSW, LPMA, booklet. Roberts, C 2009, “CORS GNSS networks: A Superior Infrastructure for Precision Agriculture”, Southern Precision Agriculture Association Conference, Adelaide, 4 September South Australian CORS Network, viewed 29 May 2011,. Victoria Department of Sustainability and Environment, Vicmap Position – GPS net, DSE, booklet. VicMap Position - GPSnet 2011, VicMap Position – GPSnet, viewed 29 May 2011.