Impact of Multiple Frequency GNSS Signals on Future Regional GNSS Services

The key limitation of existing Real-Time Kinematic (RTK) systems is the service distances between reference stations and user receivers due to the impact of distance-dependent biases such as orbit error, and ionospheric and tropospheric signal delay. In current Network-RTK implementations, the inter-station distance is typically 70km to 90km. If coverage were to be extended to the whole Queensland at this density, the number of CORS receivers required would be of the order of several hundred, representing tens of millions of dollars in installation costs, and millions per annum for operations. However, use of multiple-frequency GNSS signals and/or multiple satellite GNSS systems could possibly redefine future RTK services on both a regional and global basis. Possible future GNSS services could realize regional network-based RTK services at the centimetre to decimetre accuracy level. The reference stations equipped with triple-frequency GNSS receivers may be spaced up to a few hundred kilometres apart, to provide differential and