
Super-Accurate GPS Chips Coming to Smartphones in 2018 - sohkamyung
https://spectrum.ieee.org/tech-talk/semiconductors/design/superaccurate-gps-chips-coming-to-smartphones-in-2018
======
gruez
>will give the next generation of smartphones 30-centimeter accuracy instead
of today’s 5-meters

Didn't the US scramble the civilian signals specifically so it wouldn't be too
accurate? And they're just okay with civilians having access to ultra accurate
GPS receivers?

~~~
j7ake
Why would consumers want this type of accuracy ?

~~~
KGIII
I prefer results to be as close to accurate as possible. I use a dedicated
device, not a phone, when I put out game cameras or traps. The more accurate
the results, the quicker they are to check.

I guess I'd reverse the question. Why wouldn't you want the greatest level of
accuracy you can get? Maybe you want to track your property lines? Maybe you
want to accurately mark where your access point is for your septic tank? Maybe
you just want to hide Easter eggs or buried treasure?

I'm not sure why anyone would want a tool that is less accurate than it can
be, assuming it is also reasonably affordable.

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colinwilson
As an avid hiker and runner I'm more excited to see what this will do for
things like Garmin smart watches. I run through downtown Boston a few times a
week and the accuracy is very bad at times making you look like you run much
farther than you do.

~~~
eatbitseveryday
Do you run the same path frequently? When I do, I keep the path the same, as I
pre-calculate the distance, and can keep a watch to track my time. Thus I have
no need for path tracking.

A GPS unit is useful for assisting dynamically changing routes (e.g. driving)
or to track unknown paths (e.g. plotting your hike in snow/darkness). May I
ask what you'd need a fine-accuracy GPS unit for during a run?

~~~
colinwilson
For runs it's mostly just for fun. I use Strava so it has sections they
identify along your run that they rank you against your friends and strangers.
I do end up running very similar routes most of the time.

I mostly find the GPS invaluable in hiking. It can be a great thing to have on
the top of a mountain in the winter with low visibility. If you get up to a
summit and the weather turns, you can have the watch send you back down the
way you came. Nice and safe.

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phkahler
Accuracy vs Precision. So they can pin your position to within 30 centimeters,
but how small of changes can be detected? Can they detect relative movement on
the order of 1cm or less? that would be really useful for some things. For
example if you wanted to measure the distance between 2 points on the ground,
you don't care about offsets but do care about precision.

~~~
LeifCarrotson
Check out the documentation from Swift's Piksi receiver project for a good
introduction to existing technology:

[https://www.swiftnav.com/sites/default/files/whitepapers/loc...](https://www.swiftnav.com/sites/default/files/whitepapers/localization_white_paper_052617.pdf)

The technology in good receivers like the Piksi is slowly drifting into
consumer-level hardware. You need to correct for such errors as:

1\. Jitter in the code phase vs. phase-locked-loop. As the article describes,
most existing codes are long and slow, with bandwidths on the order of 300 m
(specifically, 1.023 MHz). The receiver can measure the exact time at which
this code changes to get your existing resolution, but the L5/E5 bands are at
20 MHz.

2\. Integer offsets when interpreting the carrier frequency. The above slow
codes are transmitted on a carrier at 1-2 GHz, giving much higher resolution,
but there's no information in the signal as to which particular node of the
carrier frequency you're observing. Comparing to a known location, and
improving your guess over time, can let you make use of this information.

3\. Unknown, slowly drifting ionospheric delay. Typically fixed in industrial
or agricultural applications by using a base station and radio link to tell
your remote link that the base station (which is bolted to a big chunk of
concrete) is now reporting that it's 20 cm from where it was an hour ago, and
the remote unit should probably just adjust any measurements by that much.

I only have enough knowledge of the system to be dangerous, but I've wondered
whether it would be possible to correct for #3 at a consumer level with a
phone app. If you had thousands of phones cooperating in a city, at any given
time many would be stationary, even charging or on wifi, and you could
theoretically trade off roles as reference base stations and remote receivers.
I think it would require a lot more low-level access to the GPS chip than
generic Apple/Android phones give you, but it's an idea - feel free to take it
and run if you like it.

To answer the basic question - common NMEA protocol returns GPS data with
latitude formatted as DDMM.MMMMM (Degrees, minutes, and decimal minutes) and
longitude in DDDMM.MMMMM format. Four digits of precision get you a precision
of about 1.6 meters, depending on where you are on the Earth, but that doesn't
mean you have that level of accuracy.

~~~
mookerji
(disclosure: I'm an engineer at Swift Navigation)

Indeed, carrier phase and multi-frequency+constellation measurements are
drifting into consumer hardware, but I can say that it's probably going to be
a Good Long While before we full realize its benefits. The use of cell phones
(and cheap cell phone antennas) is an active area of research, particularly
for organizations aiming to make high-accuracy GNSS positioning widely
accessible outside of specialty markets (i.e., agriculture and surveying).
It's an interesting area to be in for sure:

    
    
      - http://gpsworld.com/innovation-precise-positioning-using-raw-gps-measurements-from-android-smartphones/
      -
     https://radionavlab.ae.utexas.edu/images/stories/files/papers/inPhoneCdgnssIonPlans2016.pdf
    

The base station network density question @ac29 points out later is a
compelling reason for some of this.

(Shill: We're hiring for firmware engineers right now, focused on a variety of
different areas: embedded Linux, DSP basebands (C), and navigation algorithms
(C++) design and implementation. See [https://jobs.lever.co/swift-
nav](https://jobs.lever.co/swift-nav) for more details or email
jobs@swiftnav.com.)

------
matt_kantor
Why was "oil and gas exploration" an early adopter here? Can anyone connect
the dots for me?

I wouldn't expect interesting oil/gas pockets to have <5m lateral diameter,
but then again I know very little about that industry.

~~~
hasperdi
I'm not in the oil industry. But I imagine this is a great improvement for un-
anchored / thrusters positioned platforms.

~~~
DigitalJack
I'm pretty sure this is it. They have a drill that is essentially an anchor
and the rest of the platform is essentially a floating quadcopter maintaining
position.

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tomlock
I may just be a super-cynical ad-tech exile, but I see this as a path to
getting shown more ridiculously well-targeted ads based on the places and
stores I've been in. Beacons haven't taken off and I'm glad they haven't. I'd
really prefer a GPS in my phone with a similar granularity to the one I have
now. Google's notifications that I should review places I've been are creepy
enough.

~~~
haikuginger
It's almost as though using a phone whose operating system is created and
maintained by an advertising company isn't the best idea if you want to keep
things like your location private.

~~~
tomlock
Apple is also an advertising company - they have unique IDs with your personal
information pinned to them, and they sell ads based on your location, too.

~~~
mikeyouse
You can change your advertising ID any time you want -- and almost none of
their revenue comes from ad sales. In 2016, $190B of their $215B in sales was
definitively _not_ from ad sales, and the $25B services category that would
include ad sales also includes the percentage of sales from the App Store,
Apple Pay, Apple Care, iCloud.. etc. Ad sales are immaterial to their business
model.

~~~
tomlock
Apple makes revenue from ad sales - Apple is therefore also an advertising
company.

They're the lesser of two evils. Still an evil, though.

~~~
mikeyouse
> Apple makes revenue from ad sales

Is that even true? They pulled the plug on mobile ad sales a year or two ago
([http://appleinsider.com/articles/16/01/18/after-
abandoning-i...](http://appleinsider.com/articles/16/01/18/after-abandoning-
iad-revenue-apple-can-reintroduce-an-ad-free-internet-)), where else would
they make advertising revenue?

And in any case, a company who makes 99.9% of their revenue off of non-ad
sales is definitely would never be categorized as an advertising company. My
grocery store is paid to put crest at eye-level, that doesn't make them an
advertising company...

~~~
darren_
The iTunes store shows ads, and they can be demographically and geographically
targeted.

I don't know if they're ads or not but there's also location based app
suggestions too.

disclaimer: i'm a googler so glass house throwing stones etc, and of course
the scale is way different

------
lordnacho
Wow, it's within a few cm. I wonder if Google Maps and those guys actually
move the buildings around due to seismic events?

~~~
dmd
[https://theconversation.com/australia-on-the-move-how-gps-
ke...](https://theconversation.com/australia-on-the-move-how-gps-keeps-up-
with-a-continent-in-constant-motion-71883)

------
lhl
If anyone works in the field, I'd be interested in how this dual signal
(L1/L5) chip interacts with the RTK/CPGPS [1] (which improves accuracy down to
1-3cm already (at the cost of using multiple GPS units)).

RTK is commonly used in survey drones, and kits are available for about $1K.

[1]
[https://en.wikipedia.org/wiki/Real_Time_Kinematic](https://en.wikipedia.org/wiki/Real_Time_Kinematic)

~~~
Deadolus
RTK uses a fixed base station, ideally you know _exactly_ where it is so that
you know the _exact_ location of your mobile unit (else you will at least get
a pretty good relative position).

With the new chips, Broadcom, u-blox and others are bringing to market now you
are no longer dependend on a base station to get cm-level accuracy. Instead
they exploit the different properties of the L1/L5 frequencies to infer stuff
about e.g. the atmosphere, as the different frequencies are altered in
different ways while travelling to earth[2]. The system can thus reduce its
margins of errors[1] in the position calculations. So they are not
"interacting" with RTK in any way. The chips are also much cheaper than your
quoted $1K price tag.

Disclosure: I work for u-blox, but not an expert in GNSS calculations

[1]
[https://en.wikipedia.org/wiki/Error_analysis_for_the_Global_...](https://en.wikipedia.org/wiki/Error_analysis_for_the_Global_Positioning_System)
[2]
[https://www.e-education.psu.edu/geog862/node/1715](https://www.e-education.psu.edu/geog862/node/1715)

~~~
alberto_ol
are there already Ublox chips that use the L5 frequency?

~~~
Deadolus
Not at the moment.

------
Animats
15cm GPS accuracy has been available commercially since about 2002. Trimble
and Novatel both sold units. But you had to get a subscription to a service
which had a network of ground stations measuring propagation errors through
the atmosphere. The correction signals came in from a geosync satellite. You
also had to be able to see about five satellites.

~~~
ac29
~1cm accuracy is available now from dozens of companies, and doesn't require a
subscription (though subscription services are still available).

~~~
grandalf
link(s)?

~~~
ac29
Leica Geosystems [0], Topcon Positioning Systems [1], and Trimble [2] are the
companies I deal with most often, but there are many, many others.

[0] [http://leica-geosystems.com/en-us](http://leica-geosystems.com/en-us)

[1] [https://www.topconpositioning.com/](https://www.topconpositioning.com/)

[2] [http://www.trimble.com/](http://www.trimble.com/)

------
dmckeon
Down to 30cm - good! Now all we need is a GPS-enabled app for urban
pedestrians that reminds them to look left or right just before they step off
a curb into oncoming traffic.

~~~
js2
As a runner I’d appreciate the corresponding app to remind drivers to look
both ways before turning right.

~~~
seansmccullough
It's always the right turners who just stare left and then go...

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StillBored
The siri/android problem doesn't seem to happen with the dedicated GPS nav
systems I have. Maybe its a sample rate problem with phones (trying to save
power), or just better smoothing, or relative plotting with the dedicated
receivers. 5M is less than the distance between most highways and their
frontage roads, so blaming the GPS signal itself for being unable to determine
if your on the frontage road 15 seconds after you got on the highway is pretty
lame.

I frequently run my ten year old TomTom, alongside my wifes iphone or my
android on road trips. The tomtom is pretty much always dead on with respect
to lanes/turning/etc, while the iphone/android regularly feeds us crap. That
said, I would kill for google maps (pc browser version) style route planning
on the tomtom where you can click various roads and get time estimates even if
goggle doesn't think its a good route.

------
antonioalegria
How does this compare with iPhone 8/X, which supports the Galileo system, as
well as GPS and GLONASS?

~~~
JshWright
The vast majority of phones out there support GPS and GLONASS (as well as
ESA's Galileo), and have for years. That's not new to the iPhone 8 (surely the
iPhone has has this before as well, right?)

Using the other constellations helps you see more sats, but it doesn't really
help deal with the reflection issue in urban environments. The "big deal"
about this chip is that is uses the new L5 signal (and it's equivalent in
other constellations). Previously that has only been available in very
expensive hardware.

~~~
mkstowegnv
Gallileo support in new cell phones only barely started this year
[https://www.gsc-europa.eu/galileo-gsc-
overview/services/gali...](https://www.gsc-europa.eu/galileo-gsc-
overview/services/galileo-initial-services/galileo-enabled-devices)

~~~
JshWright
Yeah, hence the parenthetical addition. GPS and GLONASS have been around for
quite some time though.

------
roberttod
> In a city, the satellite’s signals reach the receiver both directly and by
> bouncing off of one or more buildings. The direct signal and any reflections
> arrive at slightly different times and if they overlap, they add up to form
> a sort of signal blob. The receiver is looking for the peak of that blob to
> fix the time of arrival.

> However, L5 signals are so brief that the reflections are unlikely to
> overlap with the direct signal. The receiver chip can simply ignore any
> signal after the first one it receives, which is the direct path.

Can someone explain this? Surely the first signal received will always be the
direct signal, how could you receive signals from reflections first?

~~~
Brotkrumen
The key word here is "overlapping". I think the "old" L1 signal was long
enough for the direct signal to arrive first, then have the reflected signal
arrive while the direct signal was still being received. This would create the
"signal blob".

So yes, the direct signal always arrives first, but gets messed up during
receiving by the reflected signal. The L5 signal is so short, that the
likelihood of reflections overlapping is reduced. Think: so short that the
signal starts and finishes during the time it takes a radio wave to propagate
1 meter through air or so.

------
lwansbrough
I wonder if we'll see these in Microsoft's 2018 HoloLens. 1ft accuracy +
spatial mapping = a global spatial mesh with countless commercial
applications.

~~~
shpx
Hololens uses
[https://en.wikipedia.org/wiki/Photogrammetry](https://en.wikipedia.org/wiki/Photogrammetry)
which is already more accurate (just watch a demo), so more accurate GPS won't
have an effect here.

Photogrammetry is what humans do, and it doesn't cost billions of dollars.

[https://en.wikipedia.org/wiki/Global_Positioning_System#Deve...](https://en.wikipedia.org/wiki/Global_Positioning_System#Development)

[http://nation.time.com/2012/05/21/how-much-does-gps-
cost/](http://nation.time.com/2012/05/21/how-much-does-gps-cost/)

~~~
lwansbrough
Can a human tell where in the world they are without already knowing something
about the environment?

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mkoster
Does anyone know if we will be able to access the OS-NMA messages and manually
verify them, or if the chip just discards any forged messages?

The reason why I ask: If we can get highly accurate and signed timing data it
will have a huge impact on distributed systems. If the signature is accessible
from the API it could be included in a DB transaction that every node could
verify.

------
itissid
The current chip sets for enthusiasts cost ~600-1200$
[http://www.rtklib.com/](http://www.rtklib.com/) I hope these come in decent
packages to be usable for enthusiasts and are cheaper..

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nradov
Hopefully those chips will also be integrated into wearable fitness trackers.

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Sami_Lehtinen
QZSS != GNSS = FAIL. But otherwise nice and very welcome development.

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stevefeinstein
This is great, and will definitely cut down on collateral damage and allow for
precision strikes when causing enemies of the state to become room
temperature.

------
throwaway2016a
This seems like a great step. I had no idea the accuracy was only 5 meters
right now. My phone feels like it is more accurate than (like 2 meters) that
but I suppose that is because software does a good job at guessing where you
actually are?

It's awesome that it is half the power of current chips too. Because I think
smart phone users care more about battery life than accuracy.

Edit: Changed my messages because I reread the article and caught something I
missed the first time. I missed the power usage statement the first time.

~~~
haser_au
Half the power consumption, according to the article.

------
blt
Good news for robotics! We have really benefitted from the cheap sensors
manufactured for the smartphone industry.

------
dramm
Siri navigation? After you have already looked up the route in Google Maps?
What strange world does this writer live in?

~~~
fps
Yeah, the intro to the article made it pretty clear that this writer doesn't
know the first thing about mobile technology. I think, in his mind, "Siri" is
the name for mobile text to speech.

