[terryf]

Interesting - as I'm in the middle of one of the red blobs on the map and just used my phone with google maps to drive around. It worked fine. All the local services that rely on positioning via phones seemed to work fine as well.

I wonder how the jamming works - is it just for higher altitudes or maybe it only affects GPS and my phone also uses GLONASS or something?

[jcfrei]

On your phone the GPS is just one input to determine its position. It's most likely also triangulating cell phone towers. Get an app that only shows GPS data and check if you see coordinates jumping around.

[themoonisachees]

Google maps (and your phone's location services) seldom rely only on GPS.

For one, accelerometer-based location has become pretty good. You can usually get by for a few kilometers on the average road.

For two, Google maps is aware that you are driving, and this it sticks to roads, especially ones that are on your itinerary, because of your GPS registers as the middle of a field, it's more likely that you're experiencing GPS issues rather than you driving at 130km/h in a potato field.

Finally, location services are amplified by nearby wifi signals, mapped by google with street view. Your phone can say "here is the Mac address of every wifi network I can see and a rough estimate of my position" and Google's services can very accurately triangulate where you are.

[cft]

Does accelerometer-based location algorithm integrate the acceleration readings to get the phone displacement? Is it a part of the phone operating systems ?

[themoonisachees]

It tries. Accelerometer-based positioning is best used with camera displacement, which isn't used in Google maps driving mode (though there was? Is? An experimental on-foot mode that showed directions in AR).

the accel-based positioning I'm pretty sure is implemented app-side, not os-side, but I could be mistaken.

[rightbyte]

Probably not. Maybe to like know where you are turning in a round about. But the drift is too big to be useful over any distance.

[tjohns]

Aircraft fly higher, which means they pick up ground radio signals from much further away - both good (ATC communication, ground-based navigation beacons) and bad (intentional jamming).

On the ground, the radio horizon is about 20-40 miles. In the air, the radio horizon is about 200-400 miles.