CR Kennedy, Leica Geosystems partner in Australia, has won a tender to supply new Continuously Operating Reference Stations (CORS) to Spatial Information Infrastructure of the Department of Sustainability and Environment (DSE) in Victoria. The tender requested Global Navigation Satellite Systems (GNSS) equipment to support GPSnet modernization and densification.
GPSnet (www.land.vic.gov.au/gpsnet) is a cooperative network of 31 GNSS reference stations located across Victoria. In the past few years the network has grown with the assistance of industry, academia and community hosts, partners and contributors from a few reference stations providing static data for post processing to a comprehensive network providing both post and real time processing services. The real-time element provides a high accuracy (<±2 cm horizontal) Network RTK (NRTK) service covering Melbourne and environs (an area covering approximately 200 km east west from Ballarat to Ellinbank and 100 km north south from The Rip of Port Philip to Whittlesea), available direct to a GNSS rover via mobile phone using services such as Telstra Next G. Real-time network differential GPS (NDGPS) corrections across and beyond Victoria to <1 m accuracy and single baseline Real-Time Kinematic (RTK) to centimetric accuracy from GPSnet data streaming sites is also available.
Part of the nationawide GNSS CORS network
Densification of the CORS network will increase the service coverage of NRTK across Victoria providing additional reliability and robustness. Modernization of GPSnet will increase the progress of migration to a GNSS (GPS, GLONASS and potentially Galileo) CORS infrastructure capability.
It is also anticipated that GNSS CORS equipment acquired through this tender will be deployed into Victoria’s GPSnet as a part of the AuScope Geospatial Infrastructure to be installed over a 5 year period (2007-2011) ultimately forming part of the nationwide GNSS CORS network of approximately 100 sites (www.auscope.org.au/).
CR Kennedy has already delivered the seven new dedicated Leica GRX1200 GG Pro GNSS units and a combination of standard and choke ring GNSS antennas from Leica Geosystems. The Leica Geosystems choke ring antenna guarantees uncompromising phase centre stability (<1 mm), its characteristic and proven design effectively suppresses multipath effects and its "all-in-view tracking" receives all available GNSS signals.
GNSS and RTK technology
The Leica GRX1200 GG Pro is a state of the art reference receiver meeting all the strict operational terms associated with the tender. The receiver has built-in Ethernet connectivity, external oscillator and event input and PPS output. RINEX files for post-processing applications can be logged to the receiver’s CF card, which means that no external converters are required and data handling is simplified. The ultra precise GNSS measurement engine supports both GPS L2C signals and GLONASS satellites providing immediate benefit by having up to 100 % more satellites available than GPS alone. These systems are designed with an inherent upgrade path to facilitate the tracking future GNSS signals, such as GPS L5, Galileo and Chinese Beidou-2 (Compass). For RTK applications, the availability of three GPS carrier signals, L1, L2 & L5 will have important advantages for ambiguity resolution and bias estimation such as multipath and also provide an increase in the redundancy of observations.
