How does Google calculate my location on a desktop

Question

Right this is confusing me quite a bit  i m not sure if any of you have noticed or used the  my location  feature on google maps using your desktop  or none GPS none mobile device    If you have a browser with google gears  easiest to use is Google Chrome  then you will have a blue circle above the zoom function in Google Maps  when clicked  without being logged into my  Google Account  using standard Wi Fi to my own personal router and a normal internet connection to my ISP  it somehow manages to pinpoint my exact location with a 100  accuracy  at this moment in time    How does it do it  they breifly mention it here but it doesn t quite explain it  it says that my browser knows where i am        i am baffled  how   I am intrigued because I would love to integrate it in the future of my programming projects  just like some background understanding and it doesn t seem too well documented at the moment

User · Answer

I ve finally worked it out   The biggest issue is how they managed to work out what Wireless networks were around me and how do they know where these networks are   It  seems  to be something similar to this    skyhookwireless com  or similar  Company has mapped the location of many wireless access points  i assume by similar means that google streetview went around and picked up all the photos  Using Google gears and my browser  we can report which wireless networks i see and have around me Compare these wireless points to their geolocation and triangulate my position    Reference  Slashdot

User · Answer

I know you can look up IP address to get approximate location  but it s not always accurate   Perhaps they re using that   update      Typically  your browser uses   information about the Wi-Fi access   points around you to estimate your   location  If no Wi-Fi access points   are in range  or your computer doesn t   have Wi-Fi  it may resort to using   your computer s IP address to get an   approximate location

User · Answer

It is possible get your approximate locate based on your IP address  wireless or fixed    See for example hostip info or maxmind which basically provide a mapping from IP address to geographical coordinates  The probably use many kinds of heuristics and datasources  This kind of system has probably enough accuracy to put you in right major city  in most cases   Google probably uses somewhat similar approach in addition to WiFi tricks

User · Answer

I am currently in Tokyo  and I used to be in Switzerland  Yet  my location until some days ago was not pinpinted exactly  except in the broad Tokyo area  Today I tried  and I appear to be in Switzerland  How   Well the secret is that I am now connected through wireless  and my wireless router has been identified  thanks to association to other wifis around me at that time  in a very accurate area in Switzerland  Now  my wifi moved to Tokyo  but the queried system still thinks the wifi router is in Switzerland  because either it has no information about the additional wifis surrounding me right now  or it cannot sort out the conflicting info  namely  the specific info about my wifi router against my ip geolocation  which pinpoints me in the far east    So  to answer your question  google  or someone for him  did  wardriving  around  mapping the wifi presence  Every time a query is performed to the system  probably in compliance with the W3C draft for the geolocation API  your computer sends the wifi identifiers it sees  and the system does two things    queries its database if geolocation exists for some of the wifis you passed  and returns the  wardrived  position if found  eventually with triangulation if intensities are present  The more wifi networks around  the higher is the accuracy of the positioning  adds additional networks you see that are currently not in the database to their database  so they can be reused later    As you see  the system builds up by itself  The only thing you need is good seeding  After that  it extends in  50 meters chunks   the range of a newly found wifi connection    Of course  if you really want the system go banana  you can start exchanging wifi routers around the globe with fellow revolutionaries of the no-global-positioning movement

User · Answer

It s a lot more simple that you think  You ve signed into both your mobile and Chrome on your desktop using the same Google account  Google simply expect you will have your mobile with you most of the time  They take the location data from your phone and assume the location of your current desktop session is the same   I proved this by RDPing into my Windows machine at home from work and checking Google maps remotely  It show my location as the same as Chrome on Linux at work   If you don t have a mobile that is signed into Google then all they can do is lookup GeoIP data for the IP address assigned by your ISP  It will typically be wildly inaccurate

User · Answer

They use a combination of IP geolocation  as well as comparing the results of a scan for nearby wireless networks with a database on their side  which is built by collecting GPS coordinates alongside wifi scan data when Android phone users use their GPS

User · Answer

Rejecting the WiFi networks idea   Sorry folks    I don t see it  Using WiFi networks around you seems to be a highly inaccurate and ineffective method of collecting data  WiFi networks these days simply don t stay long in one place   Think about it  the WiFi networks change every day  Not to mention MiFi and Adhoc networks which are  designed  to be mobile and travel with the users  Equipment breaks  network settings change  people move    Relying on  WiFi Networks  in your area seems highly inaccurate and in the end may not even offer a significant improvement in granularity over IP lookup   I think the idea that iPhone users are  scanning and sending  the WiFi survey data back to google  and the wardriving  perhaps in conjunction with the Google Maps  Street View  mapping might seem like a very possible method of collecting this data however  in practicality  it does not work as a business model   Oh and btw  I forgot to mention in my prior post    when I originally pulled my location the time I was pinpointed  precisely  on the map I was connecting to a router from my desktop over an ethernet connection  I don t have a WiFi card on my desktop    So if that  nearby WiFi networks  theory was true    then I shouldn t have been able to pinpoint my location with such precision   I ll call my ISP  SKyrim  and ask them as to whether they share their network topology to enable geolocation on their networks

User · Answer

According to Google Maps  own help

User · Answer

So Google keep records of Wifi router location by using any cellphone GPS that connected to that router when you use Google maps or location on cellphone  then google knows every device that connected to that Wifi router uses the same location  when GPS off or no cellphone connected to router Google uses IP geolocation

[geolocation] How does Google calculate my location on a desktop?

Examples related to geolocation

Examples related to google-gears

Examples related to google-latitude