Rethinking GPS: Engineering Next-Gen Location at Uber
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Re: Rethinking GPS: Engineering Next-Gen Location at Uber
#2Amusing that they don't mention that they're able to better predict your location because of your phone's Wi-Fi.
Tracking people is necessary [0] as Uber needs to provide better services.
[0] https://www.npr.org/sections/alltechconsidered/2016/12/01/50...
Re: Rethinking GPS: Engineering Next-Gen Location at Uber
#3tl;dr using 3D maps to build a model of GPS shadows for receiver and satellite locations, and using the relative signal strength for each satellite, plus that model, to come up with a more accurate receiver location.
Original UCSB site: https://tia.ucsb.edu/about-tia/success-stories/shadowmaps/
A more detailed writeup by the original authors: http://insidegnss.com/auto/sepoct15-MADHOW_0.pdf
Re: Rethinking GPS: Engineering Next-Gen Location at Uber
#4> The use of particle filters necessitates a level of server affinity. Each new request to our service must be routed to the same back-end server for processing in order to update the correct particle filter.
Was implementing this on the client device considered? What were the motivations for this design?
Re: Rethinking GPS: Engineering Next-Gen Location at Uber
#5Why do they need a 3d map to begin with?
Following their example of which side of the canyon the phone is, given the snr of sat b,c,d they can guess the side of the street.
If it's possible then being shadowed by an actual building, a construction site or a delivery truck amounts to the same result (but I guess the snr would vary between these 3 situations). Hence, why the need for the 3d model?
Re: Rethinking GPS: Engineering Next-Gen Location at Uber
#6Why do they need a 3d map to begin with? Following their example of which side of the canyon the phone is, given the snr of sat b,c,d they can guess the side of the street. If it's possible then being shadowed by an actual building, a construction site or a delivery truck amounts to the same result (but I guess the snr would vary between these 3 situations). Hence, why the need for the 3d model?
Long term thinking?
Re: Rethinking GPS: Engineering Next-Gen Location at Uber
#7Amusing that they don't mention that they're able to better predict your location because of your phone's Wi-Fi. Tracking people is necessary [0] as Uber needs to provide better services . [0] https://www.npr.org/sections/alltechconsidered/2016/12/01/50...
Yeah, it's not like Uber did not hire Waleed Kadous away from Google, where he had led Android and indoor positioning, which make plenty of use of fused location. I bet he was involved in recruiting these folks (he approached someone I know in a related area. It seemed like they were investing heavily in every technology to sense the world, which makes sense for them).
Re: Rethinking GPS: Engineering Next-Gen Location at Uber
#8Previous discussion: https://news.ycombinator.com/item?id=16887276
Re: Rethinking GPS: Engineering Next-Gen Location at Uber
#9Why do they need a 3d map to begin with? Following their example of which side of the canyon the phone is, given the snr of sat b,c,d they can guess the side of the street. If it's possible then being shadowed by an actual building, a construction site or a delivery truck amounts to the same result (but I guess the snr would vary between these 3 situations). Hence, why the need for the 3d model?
The example is simplistic, it's 3d space. It's not just which side of the street but buildings could be in any direction at various angles.
Re: Rethinking GPS: Engineering Next-Gen Location at Uber
#10A big problem with Uber/Lyft is that drivers take all these fancy calculated positions and plug them into a standard navigation app, which can direct the driver to the completely wrong side of a large block. (Addresses are not very granular in a city.) It’s interesting to me why Uber/Lyft allow this.