Re:Reduce GPS data error on Android with Kalman filter and a...
by Gen1us2k on Wednesday March 21, 2018 @01:29AM
(#16635709)
We use geohash because it's really fast and we can control precision. We don't need to store any information about grid and we don't need to convert coordinates to spherical view.
Perhaps they can take advantage of the better locality of Z index compared to flat index, and/or they want to store higher precision and do lookups with varying precisions (grid sizes)?