How do they have GPS in the sewer? Phones don't track your position with acceleration data
@matrix
You know I thought about that once when I was like 13. How many turns would be needed to narrow down to an acceptable number of possible locations, augmented by where the device was set up and/or last seen?
@r000t I think, in 2D, if you keep turning in the same direction, everytime you turn 90 degrees you cut the possible area in half, if you alternate directions second turn cuts 75%, so pretty quick.
The problem IRL is that the accelerometer isn't perfect and the error keeps stacking.
@matrix
I was thinking more like, there's only so many places that have these three turns this length apart and they're this extreme
Works less in places with perfect grids, probably works better in suburban developments which are intentionally twisty
