GNSS (Global Navigation Satellite System ) is an acronym for a network of satellites that transmit signals used for positioning and navigation anywhere around the globe; on land, in the air or at sea. The US GPS, the Russian GLONASS and the upcoming European GALILEO system are examples of GNSS.
The systems themselves have a positional accuracy in the order of ten's of meters, which is more than adequate for most users. However, there are a large number of users who need much higher accuracy they will need to employ 'differential techniques'.
This process simply involves the placement of a GNSS receiver at a known location (Base) and the measurement errors that cause position errors are provided as 'corrections' to the GPS unit whose position we need to determine (Rover). These corrections can be provided real-time if necessary. There are many Correction Services available and improve the accuracy to the order of a few meters - this accuracy is perfectly suitable for most applications.
For the GNSS user who requires accuracies in the sub-meter to millimeter level, (Real Time Kinematic or RTK), a dedicated wireless data service is necessary to 'broadcast' these corrections - ArWest narrow band radios are tailor made for these applications. Easy to use, easy to set up and with advanced modulation techniques, SuperScanning and forward error correction ensure the quality, reliability and accuracy of the data.