Hacker News new | ask | show | jobs
by maym86 2893 days ago
You won't get close to GPS accuracy with these. The uncertainty from cell tower triangulation is huge (relatively). But yes, some kind of beacon that works like GPS on a local scale or detection of known mapped landmarks could be used for corrections but there are issues with these too. These could assist GPS location rather than replace it entirely.
1 comments
c22 2892 days ago
> These could assist GPS location rather than replace it entirely.

Of course, that was the proposal. There's more datapoints if you're willing to get creative, wifi networks (already used for this), cooperative comparison with other mobile devices in a local meshnet, acoustic cues from the environment, machine analysis of captured images, etc. Obviously dead reckoning without gps is going to require a multi-pronged approach.

link
maym86 2892 days ago
> cooperative comparison with other mobile devices in a local meshnet

Please explain how this will work?

link
natosaichek 2892 days ago
I could imagine a secure location service that allows your phone to compare its current expected position with other nearby phones' expectations of their positions. If it's over bluetooth or wifi, the positions should be within meters of each other. This could provide an input to a kalmann filter type position estimator to help reduce drift as you (for example) walk down the street.
link
maym86 2889 days ago
This doesn't make a lot of sense tbh.
link
natosaichek 2888 days ago
What do you mean?

You don't think such a system is practical, or you don't think such a system is technologically feasible?

Or you just don't understand the system I'm describing?

link
maym86 2888 days ago
I think there are both feasibility and practicality issues with the cooperative estimation scheme you are describing. Without already knowing where the phones are very accuratly there will be a lot of noise. Would need a lot more detail to really understand what you intend but first reaction is that it'd be very difficult to do well.

If you really care you could sketch out what exactly it is and how it'd work for yourself for a couple of devices (or more) and see what issues you uncover.

link