

Think GPS is cool? IPS will blow your mind - 11031a
http://www.extremetech.com/extreme/126843-think-gps-is-cool-ips-will-blow-your-mind

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drats
Only in the hyperventilating startup bubble world can tracking people around a
shopping mall with wifi be cooler than tracking your position anywhere on
earth with satellites that were put there by huge rockets.

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mortenjorck
I also get the feeling the author has never heard of differential GPS:
<http://en.wikipedia.org/wiki/Differential_GPS>

Which actually leads to something I've wondered about before: Why couldn't you
(with appropriate FCC clearance) set up GPS transceivers around a shopping
mall calibrated to rebroadcast the signal at the appropriate time offset? It
would work with everyone's existing hardware and be completely transparent.

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modeless
The location of each GPS transmitter must be known exactly for the
triangulation to work, and existing GPS receivers know nothing about the
location of shopping-mall transmitters. They only know about satellites.

So that's why you couldn't do this with existing receivers, but I don't know
of any reason why you couldn't make new receivers that cooperate with a new
type of ground-based transmitter built into cell towers or similar. Multipath
might be a problem but it seems surmountable. Do any radio experts here know
why nobody has done anything like this for cell phones? (The Wi-Fi/Bluetooth
positioning talked about in the article is based solely on signal strength
which is far inferior to the GPS method).

~~~
archivator
I don't think the GPS approach can work with ground stations - what GPS has
going for it is line-of-sight to the satellites. Multipath would be a hell of
an issue in an urban environment.

That said, here's a paper describing various positioning methods -
[http://emits.esa.int/emits-doc/1-5200-RD25-Signal-
processing...](http://emits.esa.int/emits-doc/1-5200-RD25-Signal-processing-
techniques-network-aided-positioning.pdf)

EOTD looks rather interesting - <https://en.wikipedia.org/wiki/E-OTD>

~~~
jf271
WAAS is a combination of GPS and ground stations. It is accurate to about 6
feet. Widely used in aviation.

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modeless
The ground stations don't transmit to your device. WAAS still needs the
satellite signals to work and so won't help indoor reception problems.

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toomuchtodo
Correct. The ground reference stations multiplex their data to the WAAS
satellite, which then pushes the data on WAAS-specific channels (hence, why
your GPS receiver specifically needs to be built to support WAAS)

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ChuckMcM
As a robotics hobbyist I've done a lot of research into the 'localization'
problem (which for robot folks is localizing where you are relative to the
space around you). And there are lots of ways to do it, some more interesting
than others. The simplest being landmark navigation. Sebastian Thrun of the
self driving car fame did some interesting graduate work in Germany where a
robot uses the doorways to figure out what room it was in and then could
navigate to any other room.

However what some people fail to realize is that _stores_ really don't want
this technology to exist. You see they, like Casinos and other places with
'impulse actions' want you to wander around looking for your target and being
exposed to various other temptations. How much less per shopper would you
imagine there would be if a shopper had a pre-planned route available for the
three things they needed at a Target or a Walmart?

A really simple solution would be to program the ceiling of a place into an
app. When you're looking at your phone, its front facing camera can look past
you to the ceiling and figure out where you are. Roboticists have known for a
while that ceilings are remarkably good navigation references, try as you
might they are often quite different to the discerning camera.

~~~
minikites
"Roboticists have known for a while that ceilings are remarkably good
navigation references, try as you might they are often quite different to the
discerning camera."

Would this work in an absolute sense, providing absolute location, or in a
relative sense, like an optical mouse, sampling the ceiling and comparing each
sample to the previous?

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stonemetal
It ought to be good enough for absolute position. The general arrangement of
lights, air vent, smoke alarm, sprinkler, motion detector, and wall proximity
are more than likely unique.

~~~
pavel_lishin
Assuming this technology because popular enough to affect the stores' bottom
line, how much do you think an enterprising person could charge them to
install a system specifically engineered to confuse this?

I'm thinking, Portal-like attachments in the ceiling that randomly move around
- probably at night, to avoid scaring shoppers.

Or maybe you could get away with a couple of computers hooked up to half a
dozen projectors, projecting random imagery on the ceiling. You could even do
something interesting like a rainforest canopy, clouds, etc.

~~~
ChuckMcM
I really love this visual. Black inverted beetle hump devices, masquerading as
security cameras, moving from place to place on the roof at night when the
lights are out to confuse nav algorithms that defeat 'enchhanced discovery'
layout.

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jarek
GPS categorically does not "only really operate in two dimensions." You get
altitude above mean sea level as part of the standard GPS reading.

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dholowiski
The article claims that " GPS and GLONASS can measure altitude, but generally
the data is inaccurate and too low-resolution (on the order of 10-25 meters" -
which I'm fairly sure is totally un-true.

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sern
No, it's true. The possible geometry of visible GPS satellites at any given
moment (namely that they're all above you and none are below) means that the
vertical error is pretty bad in comparison to the horizontal error.

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runjake
GPS altitude readings seemed pretty fine on the numerous mountains I've
climbed. I almost always cross-checked with a calibrated barometric altimeter.

~~~
dholowiski
Interesting. I wonder if the altitude readings were WAAS augmented, or if this
is a case where theory doesn't translate in to reality.

~~~
runjake
Ah. You may be right, there. WAAS is enabled on my GPS (a Garmin 60CSx).

Link for bystanders: <http://en.wikipedia.org/wiki/Waas>

_WAAS uses a network of ground-based reference stations, in North America and
Hawaii, to measure small variations in the GPS satellites' signals in the
western hemisphere. Measurements from the reference stations are routed to
master stations, which queue the received Deviation Correction (DC) and send
the correction messages to geostationary WAAS satellites in a timely manner
(every 5 seconds or better). Those satellites broadcast the correction
messages back to Earth, where WAAS-enabled GPS receivers use the corrections
while computing their positions to improve [3D] accuracy._

~~~
toomuchtodo
And if you need even higher resolution (centimeter resolution), use use NOAA
CORS sites (either with post-processing, or real time with their experimental
datafeed)

<http://geodesy.noaa.gov/CORS/data.shtml>

<http://beta.ngs.noaa.gov/CORS/NGSRealtimeGNSS/>

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abruzzi
One more piece of 'revolutionary technology' whose main goal seems to be to
sell me things or make me spend my money in other ways.

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baddox
When did commerce become a bad thing?

~~~
abruzzi
Commerce isn't a bad thing, but exciting new technology to try to separate me
from my money faster may be a cool thing for Google, but not for me--the
consumer. Maybe I'm weird, but I already know what I want to buy, I don't need
technology to try (and usually fail) to generate some new consumption desire.

~~~
skore
Be honest though - it's not like companies like to develop technology that has
no commercial value. Whether or not it's used in that way is a different
question, but if it's a big company developing something, you bet it went
through twenty levels of market research to make sure there is a buck to make
at the other end.

It's still your choice what you do with it once the technology gets to you. I
find it far more fruitful to look at what people do with the technology and
how _they_ end up screwing themselves with it. And by fruitful I mean
frustrating.

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technogarden
I cannot wait for this to get some adoption! I love augmented reality, but the
current state-of-the-art is not exactly suited for AR applications. If this
chip can deliver on its promises, I think we'll see an explosion in AR as it
finally starts to look real. The main problem with AR on mobile devices as I
see it is a visual one - very intense jitter due to inaccurate GPS and
gyroscope data. If IPS can pinpoint AR objects not based on visual markers or
inaccurate GPS, then I think we are quickly headed into Dennou Coil territory.
(<http://en.wikipedia.org/wiki/Denn%C5%8D_Coil>)

~~~
pirateking
I too cannot wait for true AR. I have been dreaming about making AR apps for
the iPhone since it was released, but have never found satisfactory solutions
to the positioning issues. Can't wait to play a real world RPG, with GPS used
for the world map, and IPS for dungeons with AR objects accurately placed.

(Just started Dennou Coil. It rules.)

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seldo
"Roving groups of attenuating meatbags" as a synonym for "people" is my new
favourite phrase.

~~~
trafficlight
Sounds like something out of a Neal Stephenson novel.

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smackfu
"Unlike GPS and GLONASS, there isn’t a standard way of building an indoor
positioning system. "

I don't really get it then. So Broadcom built some sensors into its latest GPS
chip, but what standard is it using to get a location from them?

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chrisa
There isn't a standard yet; wifi locationing currently requires a site survey
to gather location data. It's potentially possible to crowdsource this data,
but currently indoor location tracking has nothing like a GPS standard – each
site is different.

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54mf
Think wi-fi is cool? Sky-fi will blow your mind! It's just like wi-fi, only it
uses satellites instead of terrestrial nodes for communication.

That is to say, my main problem with IPS is that it sounds like GPS, but isn't
at all the same. One is a massive global satellite network, and the other is
glorified RFID with a hefty glob of marketing on top. Call it something else,
at least, please?

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cmcewen
This can also be done by using LEDs and smartphone cameras, which actually
gives a higher resolution. <http://www.technologyreview.com/computing/39685/>

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cypherpunks01
I was desperately hoping this would be "Interstellar Positioning System", and
not something that tracks people around in shopping malls.

~~~
Daniel_Newby
There were recent stories about using pulsars in an interstellar positioning
system.

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toomuchtodo
<http://www.bbc.co.uk/news/science-environment-17557581>

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shpoonj
Nothing pertaining to shopping malls and consumerism has ever or will ever
blow my mind.

Sorry I'm not sorry.

Can we get back to using our powers for good now?

~~~
jedahan
Just because the article shows examples of how that tech is applied to
consumerism doesn't mean thats all IPS is limited to. I'm sure you can think
of many applications that are not solely to make more money.

~~~
shpoonj
You're right... it could also be used to oppress people.

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excuse-me
We had this nearly 25years ago.
<http://www.cl.cam.ac.uk/research/dtg/attarchive/ab.html>

It was vaguely useful for finding your supervisor - assuming he a) actually
turned up at the lab and b) remembered his badge

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maeon3
A cool system would be a tool to find the location of a point relative to the
sun. So I can whip out my smartphone while in the asteroid belt and have an
intuitive metric system to identify any point in our solar system.

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pavel_lishin
You'd need at least two more points of reference, I think, in order for this
to be effective. By itself, a picture of the sun (and I'm assuming it's an
incredibly clear picture taken with a magical instrument) would only tell you
how far away from the sun you were.

With an additional known point (and an accurate date and time), you'd know
where you were within a circle around the line between those two points. That
might actually be good enough for a rough estimate, if you can assume that
you're in the plane of the solar system.

