Moving the "Blue Dot" to Improve GPS Accuracy
Andrew J. Hawkins

GPS (Global Positioning System) has been a life changer. Remember the days you used to bring along a physical map or rely on verbal directions to get where you were going? Everyone probably has at least one funny (although not funny at the time) story about getting lost while driving. Mixed exits, wrong directions, driving in circles. "He said a right at the pink building, not a left, George." We've all been there and done that.

It got a little better when the internet was born. Then came the ability to look up directions on the computer and print them out. Although that wasn't perfect, because if you made a wrong turn or a road was closed, you'd be stuck not knowing what to do next.

Now? We've got it made. Gone are the days of getting lost while driving. We just plug our destination directly into our car's navigation system or pop it into a map routing app on our smartphone and we're set. Road closed? No problem. Just keep driving and the directions will adjust.

While GPS has made getting where we're going much easier, there are some limits to its accuracy. It was originally developed in the 1970s for things that fly and thus assumed satellites would have a direct line of sight. But if you're driving in the city, for example, satellite signals can get blocked by high-rise buildings, which can refract and distort the signals – this can lead to discrepancies in perceived verse actual positioning. In most cases, this is just a small annoyance that comes along with urban living. However, with the pervasiveness of smartphones and location-based services on the rise, accuracy is now a priority for companies, such as Uber, that completely rely on GPS locations.

Enter Andrew Irish and Danny Iland from a company called Shadow Maps, which was acquired by Uber in 2016. “I usually say, when someone asks me what I do, that I move the blue dot,” Iland says. If you're familiar with Uber, when you open the app, it shows your location with a blue dot. The goal is to make the blue dot as accurate as possible to your location. If you're in a city, your blue dot could be across the street or a couple hundred feet away from where you really are, which can be a big deal when using an app like Uber. Irish and Iland used a process called occlusion modeling to develop their new technology; after beta testing in 15 cities, accuracy is about twice as good. They hope to roll the project out globally soon, so that Uber can be much more seamless for users.

If you're interested in reading more about the technology, which involves 3D maps, probability and math, you can read this article from The Verge.




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