Comment by Havoc

Thanks - that's a lot of good info :)

Sparkfun page suggests one can do some of these adjustments via software too:

https://learn.sparkfun.com/tutorials/what-is-gps-rtk/all

>1 cm accuracy is also possible with a few lower cost receivers (such as the NEO-M8T) by capturing raw streams from the GPS satellites and then post processing the logs with an open source program called RTKLIB.