I’m keen to understand how a SatNav works out how to get me from A to B.
I understand at a basic level how it receives a number of GPS signals so can work out where it is. I’d like to know what it then does to navigate me through all the different road systems to get me to my destination.
In: Technology
Not so long ago there were specialist mapping companies who drive around all day “mapping” all the roads, and they sold this database to SatNav makers. The more an area is mapped the easier it is for algorithms to work out possible routes, it’s a fairly simple matrix of options. These companies still exist, but additional data is now available.
Mobile phones share their location with Google and Apple if you let them, and so every minute of every day these phones are adding information to the databases owned by Google and Apple that map out the world. Since they’re reporting in real time, if one route isn’t moving as normal they can suggest alternatives. Based on movement patterns they can fairly accurately work out if you’re walking, using public transport, or driving. Many of the phones will be “local”, people whose own knowledge navigates issues, adding to the crowd sourced knowledge in the SatNav.
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