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A way to track people with cellphones with GPS capabilities turned off (cnbc.com)
50 points by bandbajao on July 16, 2018 | hide | past | favorite | 24 comments

There is absolutely nothing novel about using a gyroscope for tracking location; doing so predates the American civil war by 10 years and is 76 years older than sliced bread. This is clickbait for the security set, and I'm ashamed cnbc fell for it.

Disclaimer: I've done work both on side channel attacks and Android security previously.

The novel part here appears to be doing shape matching against road maps to improve accuracy. The accelerometers and gyroscope in consumer devices are so inaccurate that any track will be mostly useless after a few minutes, but if they can periodically tie that data back to known map points then accuracy improves a lot.

I'd like to see navigation apps make use of this approach when then lose GNSS signals, like in a tunnel.

Interesting, the augmentation reminds me of the Etak Navigator [1] which took a similar approach to remove accumulated errors.

[1] https://www.fastcompany.com/3047828/who-needs-gps-the-forgot...

"Snap to map" is often a setting.

It's a relatively well studied topic:


As the other reply says, this has been done for in-car systems at least since the late 90s. Heck, I had a company in the gnss space ask me this as an interview question probably 7 or 8 years ago.

In-car navigation systems do that, because they have access of stearing angles and speed.

Who cares about GPS? Cell towers track you and you can't shut that off.

As I understand it Americans have no consumer rights so your mobile carrier will happily sell you out.

You can also be tracked via local wi-fi access points. Google has built a database mapping access points to GPS coordinates. All they need is access to wi-fi information and they can find your location even if you have GPS and 4G disabled. There is really little you can do nowadays to protect your privacy.

This was actually how the very first iPhone did it’s location tracking when it didn’t have a GPS chip in it.

Uh..stop using Google..?

Every baseband (cellular chip) is mandated closed sourced, and likely backdoored.

Open source basebands NOW.

The main point here is that they're doing the tracking with a typical user mode application without access to anything that a user would know is giving away their location.

Tracking location with other sensors requires more permissions.

Can't you remove your battery?

Bingo !

So it's nothing to do with GPS then? So why is this in the title?

Perhaps the author thinks "GPS" refers to the general problem of tracking location, rather than a specific system that solves that problem?

Yes, the title is wrong.

Maybe "How smartphones can track you, even when you turn GPS off"?

But also, these researchers apparently didn't have access to cell-tower location data. Or at least, it's not mentioned in the article.

Doubt the author - and most laypeople - understand how GPS works.

Agreed, the title is very misleading.

What a dumb title. "How GPS can track you without GPS"

It is absolutely not "How GPS can track you, even when you turn it off". It's an article for the average consumer and the title should've been "how your location can be found even without GPS". This is just a clickbait-title.

TL;DR: track location using accelorometer

Wow, great invention! They should call it “inertial navigation” or something.

Doing inertial navigation with the sensors only is not going to work well. In this invention they seem to augment the sensors with external information and deduce the most probable location that way - the article is rather scant on details though.

AFAIK you can be located using cell towers both on the device side and the cell network side.

You can be located with WIFI too: if you have WIFI enabled and communicate the access point names to Google/Apple, your location can be discovered. WIFI AP locations collected beforehand (by something like the Google car or the phone itself) are matched with their known accurate position and the measured AP signal strengths.

And Bluetooth beacons can also be used for location. What else... the pictures you take with the camera and upload to a cloud storage can be used to locate you.

Having a functioning inertial navigation would be very useful for many purposes. For example, offline navigation without GPS (=longer battery life).

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