A minor nit-pick, most GPS chips will happily give out a position as a best-effort.
The actual accuracy of the measurement is given by the dilution of position (DOP), which does not appear to be in the data shown in the blog post.
This would undermine their ability to pin-point their location to within a meter, as the DOP could be very high; especially in areas with lots of tall buildings or other problematic environments.
From the comparisons, it looks like the author's GPS is getting a very low DOP (i.e. a good, clean signal from a constellation of >= 5 GPS satellites).
Either way -- still glad I don't use FaceBook, and an interesting find!
The app does not only uses GPS, it uses an underlying framework that gather position from GPS and other sources like Wifi location databases, which are much more precise.
The actual accuracy of the measurement is given by the dilution of position (DOP), which does not appear to be in the data shown in the blog post.
This would undermine their ability to pin-point their location to within a meter, as the DOP could be very high; especially in areas with lots of tall buildings or other problematic environments.
From the comparisons, it looks like the author's GPS is getting a very low DOP (i.e. a good, clean signal from a constellation of >= 5 GPS satellites).
Either way -- still glad I don't use FaceBook, and an interesting find!