read

Geolocation in today’s smartphones is a wonderful thing. The A-GPS chip in your phone talks to the satellites whizzing around above our heads and asks them where we are. If that doesn’t work then a graceful degrading process, via public wifi triangulation and then cell tower triangulation will tell our phones where we are. Except when something odd happens.

20121106-165623.jpg

And odd is the only thing you can use to describe the fact that I’m currently sitting in Teddington in Southwest London and thanks to some glitch in the matrix, either Foursquare or my phone’s A-GPS seems to think that a voting station in New England, yes, New England USA is close and local to me.

Geolocation is wonderful except when it doesn’t.

Written and posted from home (51.427051, -0.333344)
Author Logo

Gary

A self-professed map addict, Gary has worked in the mapping and location space for over 20 years through a combination of luck and occasional good judgement. Gary is co-founder of Malstow Geospatial, which provides handmade, professional geospatial consulting. A Fellow of the RGS, he tweets about maps, writes about them and even makes them.


Published

Author Logo

Chris Fleming said ...

I think this is because of the fact that Wifi signals are considered to be so accurate. But wifi AP's move around, so there should be a simple check that the location given by the Wifi signal is within range of the last cell seen. Chances are that somewhere near you is a AP that was once in New England. There could also be a "travel time" check, if it's not possible to travel the distance between the last location to this location then again it could be ignored.

Author Logo

Graham Hyde said ...

This happened to me in Leeds too. Foursquare thought I was in Leeds, AL at a polling station. Was this unique to the elections in America or pure coincidence? I haven't seen it before, or since. Very often when I'm sat on my local train at Leeds station waiting for the off and an East Coast train arrives into the platform next to me, Foursquare thinks I am at Kings Cross, Newcastle, York, Durham or Edinburgh. This must be picking something up from the on board wi-fi on the train.

Author Logo

Gary said ...

It's not just Foursquare. I'm in Istanbul at the moment. One of my Twitter clients on my phone insists that I'm in Greece whilst Twitter on the web insists that I'm still back in Richmond-upon-Thames!

Image

Mostly Maps

Maps, Geospatial and Occasionally Technology, but Mostly Maps

Take Me Home