[njoubert]

Not an annoying question whatsoever.

Dense urban environments are challenging. The error distribution is more complex there, its hard to definitively say. The numbers I'm quoting is for open sky environments where you have plenty of satellites and little multipath.

For the average end-user, these are $500 GPS units (this is the one I work on: https://www.swiftnav.com/piksi-multi). The technology is already moving down the supply chain to ~$10 GNSS units from Broadcom and ST (we're doing this: https://www.swiftnav.com/news/swift-%E2%80%8B%E2%80%8Bnaviga...)

The issue with phones is mainly an antenna issue. Your phone antenna is tiny and squeezed in alongside half a dozen other antennas and radios. This degrades the GNSS signal quality a lot. A stopgap here is external GNSS antennas for your phone: you might plug your phone into your car and get lane-accuracy turn-by-turn directions, but it's unclear when we'll have high accuracy GNSS inside phones, but most major phonemakers are indeed working on this.

[monk_e_boy]

... $10?! Really? Can we hook one up to a Raspberry Pi?

This would be a game changer for my sport (kitesurfing)

[Klathmon]

Depending on the update rates and accuracy you need, there are many commercially available GPS breakout boards and small cheap modules under about $20

I've used [1] which can be found for about $18 before on some toy projects.

[1] https://www.u-blox.com/en/product/neo-6-series

[monk_e_boy]

GPS doesn’t do height accurately :( 10m error