Global navigation satellite system
Last updated:7 June 2023
Global Navigation Satellite System (GNSS) is a generic term used to describe the US Global Positioning System (GPS) and other constellations such as the Russian Global Navigation Satellite System (GLONASS) that provide geospatial positioning across the Earth.
Over the past two decades the GNSS has proved to be a very accurate and efficient method of measuring the tectonic motion of the continents.
Why global navigation satellite system?
Trying to figure out where you are and where you're going is probably one of humanity's oldest pastimes.
Navigation and positioning are crucial to so many activities and yet the process has always been quite difficult in the past.
Currently there are a large number of Global Navigation Satellite System (GNSS) units allowing the average person to determine their current location. Consumer GNSS units come in many forms:
- mobile phone.
How good are these units?
The most recent United States Department of Defence Performance Standard Statement, September 2008 states:
"Since GPS initial operational capability (IOC) in 1993, actual GPS performance has continuously met and exceeded minimum performance levels specified in the Standard Positioning Service Performance Standard and users can generally expect improved performance over the minimum levels described here. For example, with current (2007) Signal-in-Space (SIS) accuracy, well designed GPS receivers have been achieving horizontal accuracy of 3 meters or better and vertical accuracy of 5 meters or better 95% of the time."
Survey global navigation satellite system
Surveyors are increasingly leaving behind their theodolite and using the Global Navigation Satellite System (GNSS) for most of the surveys they undertake.
Surveys such as:
- land development
- cadastral surveying
- engineering surveying
- topographic surveying
- construction surveying and set out
- urban design and planning
- hydrographic surveying
- mining surveying
- land administration
By collecting geodetic data from Global Navigation Satellite Systems (GNSS) at Continuous Operating Reference Stations (CORS), Geoscience Australia is able to measure the relative locations of points up to several thousand kilometres apart with an accuracy of several millimetres. As such, the Australian Regional GNSS Network (ARGN) operated by Geoscience Australia, is the national foundation for all positioning applications in Australia.
However, this network is sparse and tells us little about intraplate deformation and the resultant neo-tectonic strain. In addition, it does not provide good proximity for the many surveying applications that use the ARGN data.
The AuScope GNSS network which will be implemented by Geoscience Australia and the state and territory governments is designed to distribute GNSS stations along transects with a nominal spacing of 200 kilometres. Researchers will be able to monitor the deformation of the Australian continent in greater detail in near real-time, and the benefits of such a high-accuracy reference system will flow through to other areas of geoscientific research.