I bought one of the handle bar mounts for my phone and have really rather accurate Z, this is also in London too, AFAIK the software isn't using map data to hel

I bought one of the handle bar mounts for my phone and have really rather accurate Z, this is also in London too, AFAIK the software isn't using map data to help either, but surely that would be a good way of doing it too. Archway Hill has always been accurate, even on my old Garmin thing. Again I think it is mostly for faster aqusistion, as i doubt how this will help anyone who isn't keeping their phone in a correct posistion for accurate sampling. These barometric sensors weren't that accurate 5-7 years ago when I played with them, I can't imagine them helping when in a pocket or waterproofed running strap / cycle case.