There’s a wide range of different technologies available now for figuring out where you or your robot is, and the jargon can get confusing. This brief guide may help newcomers have a better understanding of the terms and alternative systems, The generic term for such systems is RTLS.
GPS (Global Positioning System) receivers use timing information from communication with multiple satellites to triangulate its position. for (military? political?) reasons, the exact timing isn’t communicated, there’s an offset so you can’t be super precise. typcial accuracy ~5m? A GPS receiver for a robot might be ~£30?
There’s also GNSS (global navigation satellite system), which GPS is a part of. GPS is actually a system run by the United States Government, but many other governments and consortiums also run similar systems. GNSS compatible receivers use several of those competing GPS-like satellite systems to get a more accurate position. Since they “fuse” data from multiple sources, they can be more accurate. They typically have an accuracy of ~1.5m and cost: ~£50
An RTK (Real-time kinematic positioning) basestation is an accessory to improve the accuracy of a GPS system. The basestation can be told exactly where it is, it can then compare that to what GPS signals are telling it where it is, and work out the offset. The correction signal can then be shared with other GNSS receivers, via a radio backhaul or via the internet using services such as rtk2go.com, to work out their position extremely accurately. Typical accuracy is around 20-50cm with an “RTK Float” solution, with an “RTK Fixed” solution being around ~1cm. An RTK-enabled receiver costs around £150.
More information on how RTK data will be available at the event can be found here.
UWB (Ultra Wide Band) is effectively a local, DIY GPS system that is typically used indoors, but can cover 100s of meters. There are multiple anchors that act in the same way as GPS satellites, each giving timing/distance information to UWB tags. By triangulating the distances, you can work out where the tag is within the range of the anchors. accuracy ~15cm, cost ~£40 (per board, tag or anchor), if you want a system at home, you’d need your own anchors, so at least £160