Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Right now as I write this I'm on a Delta flight from Atlanta heading to Boston (Technology is amazing). We are 30,000 feet in the air (probably over somewhere in D.C. area) and will be landing in an hour or so.

I was curious to see if I could find out exactly where I was according to Wifi location, so I headed over to maps.google.com.

This is what I am seeing: Google Location while on Flight

So how come I'm not seeing a triangulated position from Wifi cell towers? My friend sitting next to me thinks it's because they use Satellite (due to the fact you get errors if the plane is below 10,000 feet).

If so, why does the position point to Hartsfield Airport?

share|improve this question

closed as off topic by Ƭᴇcʜιᴇ007, slhck, Oliver Salzburg, Mike Fitzpatrick, Dave M May 24 '12 at 1:38

Questions on Super User are expected to relate to computer software or computer hardware within the scope defined by the community. Consider editing the question or leaving comments for improvement if you believe the question can be reworded to fit within the scope. Read more about reopening questions here.If this question can be reworded to fit the rules in the help center, please edit the question.

10  
There's no cell tower triangulation since you don't have any cell signal at that altitude. Your IP address probably just belongs to that airport, that's why it shows this location. –  slhck May 23 '12 at 21:31
1  
I'm curious why the close votes - I think this is a really interesting question, and I don't see how it's off-topic. (It's networking related, after all) –  Shinrai May 23 '12 at 22:20
    
WiFi wont reach you and the doppler and/or Fading noise might be intolerable if it did. Satellite is more logical reason. Good thing to know you can spoof your location in the air. ha ;p –  Tony Stewart May 23 '12 at 23:37
    
Also would like to know why my post was closed... where else on stack exchange would I post this question? –  K2xL May 24 '12 at 14:32

3 Answers 3

up vote 6 down vote accepted

Probably the IP address belongs to the airport (from which your internet access is coming, since there's no cell signal at the plane's altitude) or to a nearby tower (which might as well be installed in the airport), and the internet connection is just relayed to the aircraft.

Doing some searching around, I found this: How does Wi-Fi work on airplanes?, which describes something similar:

Ground-Based Cellular Networks In a ground-based system, an antenna located on the bottom of the plane transmits and receives signals to and from ground-based towers and works in a similar way to mobile phone networks. The plane's antenna transmits signals to the nearest tower, which in turn relays the signals to a ground station. The ground station retrieves the necessary data, which the cell tower broadcasts to the plane. As providers erect more towers, the area covered by the network expands. For faster expansion, existing cellphone towers can be fitted with the necessary equipment. Due to FCC regulations, the network is not available below 10,000 feet as the license is only for aeronautical use.

And from US Airways' description of the service:

Gogo has a network of cellular towers throughout the continental U.S. that allow transmission of broadband internet connectivity to Gogo-equipped aircraft. Three small antennas installed on the outside of the aircraft (two ATG antennas under the aircraft and one GPS antenna on top of the aircraft) receive the signal and send it to the Gogo system aboard the aircraft. The Gogo system then transmits a Wi-Fi signal inside the cabin for passenger use.

Also I would assume those services use some sort of cache, which might as well be installed at a server in Atlanta (home of Delta, as noted in a comment).

share|improve this answer
1  
And keep in mind that you're routed through their gateways...which, given that you're flying Delta, probably are in Atlanta. (I see @K2xL is a native, so this shouldn't be news) The fact that you just flew out of Hartsfield-Jackson is probably coincidental. –  Shinrai May 23 '12 at 22:15
1  
Well-noted. I forgot about this one. –  Renan May 23 '12 at 22:16
    
Doh, thanks for the response, I totally forgot to upvote this! :) –  Shinrai May 23 '12 at 22:19

Wi-Fi-based location services work by first compiling a huge database of the geographic locations of various Wi-Fi access points. They key off of the APs' BSSID (wireless MAC address).

Then they keep it up to date by having client devices report the current geo locations of any BSSIDs they see. iPhones update Apple's database, Android phones update Google's database, etc.

When the location service you're using last encountered the BSSID of the AP in your plane, the plane was at Hartsfield Atlanta Internaional Airport.

Contrary to popular misconceptions, this has nothing to do with IP address-based "GeoIP" location, which usually can't locate you any more specifically than a whole metropolitan area. Nor would it have anything to do with cell towers while you're in flight. Especially if you're on a laptop with no cellular data (3G/4G) adaptor.

share|improve this answer

30000ft is over 5 miles, there'd be a lot of WiFi router channel interference in urban areas if they could transmit 5 miles.

As for your friend's opinion he's partically correct, for security reasons modern GPS receviers will stop reporting data to the phone if it detects you're going over a certain speed or higher than a certain altitude. This is to stop people building cheap home-made Tomahawk missiles. I tried to record a flight from Heathrow to Reykjavik with GPS and it stopped just after takeoff even though the signal was fine.

share|improve this answer
    
Totally not true. I have tried to use a GPS system in a normal smartphone and it did report my correct location. Take a look at this post for more information: travel.stackexchange.com/questions/8861/… –  Derek 朕會功夫 Nov 9 at 19:30

Not the answer you're looking for? Browse other questions tagged or ask your own question.