Global Navigation Satellite System (GNSS)
GNSS provides geospatial positioning worldwide, usually within several meters, by communicating with satellites.
It encompasses various satellite constellations like
- GPS (developed by USA)
- GLONASS (Russia)
- Galileo (Europe)
- BeiDou (China)
GNSS vs. GPS?
GNSS and GPS work together, but GNSS-compatible equipment can use navigational satellites from other networks beyond the GPS system, and more satellites means increased receiver accuracy and reliability.
Difference with RTK?
GNSS offers meter-level precision, whereas RTK offers centimeter-level precision.
At WATonomous and MIT-PITT-RW, we have GNSS using the NovAtel.
What about base stations?
The idea is that you set up base stations on the ground (not satellites) at precise known GPS positions. NovAtel uses RTK to communicate with those stations, and uses the information it’s known GPS position, and that’s how it gets super accurate positioning.