
The future of GPS - sinak
http://opensignal.com/blog/2012/11/30/after-two-thousand-years-of-gps-what-next?
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stevenrace
So I've worked in this space before (realtime GPS tracking for a Fortune 100)
- reducing GPS battery drain is great...but getting the signal back to 'The
Cloud' (ie cellular) to be processed is what sucks.

And if you do barf out the data via cellular and are in cahoots with your
cellular provider - you get tower information that helps estimate/verify
location. But again, all of this eats away at whatever savings from being
impatient with the GPS signal.

With cellular and a modern LiPo, the battery life is, at best, measured in
weeks.

The 'Future' of GPS will come ~2015 when the last of the 'GPS Block-IIIA'
satellites are in orbit and we move from 50bps to 500,000bps. [1]

[1] <http://en.wikipedia.org/wiki/GPS_Block_IIIA>

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devicenull
Is this going to require new GPS receivers? I don't really see it addressed on
the wikipedia page.

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bathat
Using the new L2C signal will require a new receiver, but the current L1 (C/A)
signal will continue to be broadcast. So you will not need a new receiver to
continue the same level of service.

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Xcelerate
I don't think the future is GPS at all. I remember reading a while back about
a researcher who was working on developing tiny optical gyroscopes that were
ridiculously precise, the idea being that you can calibrate their position
once and after that all future locations are determined simply by integrating
the acceleration of the gyroscope. It would work in places that GPS can't
(like caves).

To me, that's really awesome. Personally, I think the coolest use would be in
running watches to finally get a perfectly accurate pace instead of a slowly-
updating estimate.

I'll see if I can find the link to the researcher's page.

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pithon
Dead reckoning is subject to cumulative errors, so that would have to be
REALLY accurate.

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aidenn0
To put it into perspective. Imagine a dead-reckoning system with 1ppm error
(ridiculously low) and no drift (again ridiculous). Say you use this for in-
car navigation. After driving around for 10k miles, the error is now 53 feet,
which is too great for navigation.

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HeyLaughingBoy
There's more to navigation than city streets. That accuracy would be awesome
for shipboard use.

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aidenn0
Grandparent was talking specifically about replacing GPS; I pointed out one
example where even an absurdly accurate DR system wouldn't be sufficient to
completely replace GPS.

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marcusdoran
The key line in this article: "The disadvantage with this is that you wouldn’t
get your location in real-time – it’s processed later."

The viability of this seems tied to how long 'later' is. Most consumer uses of
GPS require quick response times or you'll see a huge dropoff in usage.

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fudged71
If I'm running, or plotting a path in general, I don't need the GPS
immediately. I think instantaneous GPS is mostly used for navigational and
augmented reality purposes.

So, I could see there being some consumer uses for it, if you could
demonstrate that the power saving was worth the wait.

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7952
Post processing requires the GPS to store much more data than just a lat/lon
pair. It may need more power not less to store the extra data.

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fudged71
The paper: "Energy Efﬁcient GPS Sensing with Cloud Ofﬂoading"

[http://research.microsoft.com/pubs/172624/SenSys147-co-
gps.p...](http://research.microsoft.com/pubs/172624/SenSys147-co-gps.pdf)

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shabble
I suspect that eventually we're going to start integrating chip-scale atomic
clocks[1] into our mobile devices, which will allow a much longer
synchronisation period. Right now they're still ~35g and ~130mW power, but
that's only going down. There's going to be a whole bunch of interesting new
distributed processing stuff you can do with highly accurate synchronised
nodes; something like the Google Spanner system on a more local scale,
perhaps.

[1] [http://www.symmetricom.com/products/frequency-
references/chi...](http://www.symmetricom.com/products/frequency-
references/chip-scale-atomic-clock-csac/)

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lolryan
It looks like this is actually the strategy that Memoto is doing with its life
logging camera, which makes perfect sense in that use case: save battery by
offloading the geotagging math to the server.

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johannab
1.5 years of continuous GPS tracking with just 2AA batteries - opens up some
scary possibilities.

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ComputerGuru
I thought this was going to suggest cloud _route_ processing, like Apple
Maps/Google Maps/Nokia Here where the GPS is done on the phone, but the
routing is done in the cloud.

This is why your iPhone or Android is a hundred or even several thousand times
faster to "recalculate" a new route when you take a wrong turn than your
trusty, old Garmin. That's also why if you get lost in the middle of nowhere
w/out cellular reception, you'll be hoping your old TomTom is still in the
glove box - the maps and routing algorithms are all stored on the device
itself (though this means the data on it gets outdated and you will need to
update it, often for a price).

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serge2k
Doesn't google maps allow downloading of data to the phone for use without
internet?

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eco
Yes, you can download a fairly large region and keep it on your device. It
also downloads a route when you begin navigating so you could just turn off
your wireless once you start and it'll still get you where you are headed.

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MrUnderhill
Since it would be post processing anyway, one could possibly also make use of
corrections from IGS ( <http://igscb.jpl.nasa.gov/components/prods.html> ) (or
similar) to get extremely precise tracks. Quite nifty.

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aidenn0
Off topic, but the "flying brick" would actually let you measure longitude;
you get a lattitude fix via stars, and then the time from the position of the
flying brick (which has a known period).

