3 ms·
Lat, long, elevation. The original and best for delivering an ICBM to your door.
by JulianMorrison 8y ago
Lat, long, elevation. The original and best for delivering an ICBM to your door.
- sn41 8y agoThis may work, I should try this. Can current smartphone resolution decide the elevation difference between the first and the second floors of a building?
- Arnt 8y agoTo some degree, but not quickly and reliably.
- TheChaplain 8y agoThey already been doing that for couple of years. Maps already knows which floor I'm on in certain malls if I have the gps+wifi on.
- JulianMorrison 8y agoThis does rely on an ongoing wifi mapping effort but is the most effective for regular simple smartphones without fancy sensors.
- adrianN 8y agoGPS elevation data is pretty poor in my experience. Especially inside buildings.
- rerx 8y agoTo reliably triangulate elevation from GPS data you need quite a lot of satellites. Air pressure gives a better signal, but obviously needs to be calibrated for weather etc.
- kkarakk 8y agolots of phones have barometric sensors that can be used for more accurate elevation differences. sadly it seems to be a "premium" feature and i can't find it in any phone <300 dollars in price https://ieeexplore.ieee.org/document/6817923 https://ieeexplore.ieee.org/document/6817923
- hasperdi 8y agoThose sensors you are referring to are not reliable enough to tell elevation accurately. In addition to that, buildings may have different pressure to the outside
- kkarakk 8y agoi have successfully told the difference between the ground and 3rd floor with a galaxy note 3's barometric sensor(for triggering home routines only when actually at home vs just arriving at the location) maybe that was just a particularly good sensor...
- londons_explore 8y agoThey are sufficient if you have other phones in the same vicinity at known locations. If bobs phone is 10 meters higher than alex's phone, and they're in a 2 floor building, bob must be on the top floor and alex on the bottom. This principle can be used at scale by people like apple and google.
- BenjiWiebe 8y agoMy 2013 Moto X has a barometric sensor. When graphing the raw sensor output, I can see a ~6ft elevation change with little difficulty.