How does a device geolocation work?

Navigation
15

I've been researching ways to geolocalize a device and found these four types in a summarized way:

  
  • GPS is the most accurate way to determine positioning, but it is even energy-efficient than other options and sometimes requires a long boot time.
    •   
  • A-GPS uses triangulation between cell towers and public poles to determine location. Although not as accurate as GPS, GPS-A is sufficient for many scenarios.
    •   
  • Mobile devices that support Wi-Fi hotspots can use hotspots to determine the user's location.
    •   
  • Stationary computers without wireless devices can get approximate location information using known IP address ranges.
    •   

    GPS, A-GPS and IP I understand the whole process. But when I try to understand the geolocation through Wi-Fi, it is not clear to me, after it has processed my local network signal, what does it do next: send data via GPS? Or does the system infers positioning by IP? Do you use A-GPS?

    Looking at the W3C Geolocation API, I get to know the data I received, but I do not know how it captures (all notebooks and smartphones have dedicated hardware).

        
    asked by anonymous 31.10.2016 / 14:59

    1 answer

    7

    To help make a more accurate location is still what the Wi-Fi comes in !! When Google's cars took to the streets to take screenshots for Street View , they also started capturing data from all wireless networks that they found. Mainly name, MAC Address (it is a numeric code that in thesis would identify only each equipment) and signal level. What has generated in many places an immense discussion about invasion of privacy. As the overwhelming majority of Wi-Fi routers have a short-range signal (about 100 meters in ideal conditions), it is possible to know where the user is with certain accuracy if there are multiple routers! Just check the signal from each of them and make the process analogous to the A-GPS.

    By combining A-GPS with Wi-Fi, you can get a much more accurate initial location until the satellites of the GPS system are found. And this information, even if inaccurate, also helps locate the satellites faster, so the device knows exactly which satellites are in your region and only search for them (by querying a remote database).

    And here's one more detail of how this information gathering is done. It's not just through Street View cars, but the users themselves collaborate with this by enabling GPS on your device on first-time access.

    Read more in this article Why does Android ask to connect wi-fi while accessing GPS?

        
    02.01.2017 / 19:43
    Arduino serial port error with communication between C and Perl How to do a search ignoring accentuation in Python?