
IPhone 4S has GLONASS in addition to GPS - dchest
http://www.apple.com/iphone/specs.html
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dchest
Precisions:

    
    
      * GPS: 2.00—8.76 m
      * GLONASS: 4.46—7.38 m
      * GPS+GLONASS: 2.37—4.65 m [citation needed]
    

(source: <http://en.wikipedia.org/wiki/GLONASS>).

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singular
though off-topic and a bit of an aside, at university (I did civ eng) I learnt
that it was possible to get cm-levels of accuracy out of GPS through clever
arrangement of multiple sensors (for e.g. measuring the movement of buildings
due to subsidence, etc.)

In fact I just found a wikipedia article all about it -
<http://en.wikipedia.org/wiki/GPS_augmentation> :)

~~~
nodata
They use this on automated farms. At known co-ordinates, they stick a GPS
receiver in the ground. The difference between the known co-ordinates and what
that GPS receiver sees is then continuously transmitted to the vehicles on the
farm.

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FrojoS
Thats very interesting. Do you have any information on how much these farms
are automated?

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randomdata
Autosteer is quickly gaining in popularity. From looking at the farm equipment
in my area, I'd guess that 40% have GPS systems on their tractors/combines
based on observing the antennas on the equipment. Precision farming is
becoming important to increasing yields and reducing costs.

Right now, Kinze are heavily touting their autonomous system for grain carts:
<http://www.youtube.com/watch?v=MhA5aIw7xNk>

John Deere and CNH have similar systems in actual production, but still
require an operator to be present for safety reasons. And safety seems to be
the big limiting factor. While the technology is basically there, nobody wants
to remove the operator just yet. Though in this video, someone disabled the
safety sensors to go fully autonomous:
<http://www.youtube.com/watch?v=zU4liQvrcm4>

Most farmers are pulling their RTK data over wireless/mobile internet
connections, rather than having their own base station. I don't know of anyone
who maintains their own station. A few companies have placed base stations
around various places in the countryside and will happily sell you their data.

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k33l0r
Does anyone know if it's possible to see on an iPhone 4S if it is connected to
GLONASS satellites (either through an API call or in the settings)?

~~~
fleitz
GPS/GLOSNASS/GALLILEO work by sending time signals, there isn't really a
"connection" to a GPS satellite. Then there is the AGPS/Wifi GPS stuff which
gives you even more information. All these sources are combined mathematically
to estimate spacetime coordinates.

What the iPhone API exposes is the estimated accuracy of all these sources
combined.

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zimpenfish
I wonder if that's causing the odd jumping about I'm seeing on the 4S compared
with the stable tracking of the 4.

~~~
foobarbazetc
GLONASS+GPS is more accurate than just GPS, so the answer to your question is
no. :)

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zimpenfish
Only if your software is aware and dealing with it correctly, I'm guessing.

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fleitz
There isn't a GPS / Galileo / GLONASS / AGPS api in iPhone, you just get
location data.

Apple generally doesn't expose APIs that require working knowledge of general
relativity.

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wingerlang
Just for accuracy? What exactly does this mean (why is it on top of HN).

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iqster
Better accuracy is a big deal. For instance, it improves the quality of
Augmented Reality applications on mobile phones. It could also enable new
applications that people haven't thought about yet.

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yread
Samsung has added it to their WP7 devices with a patch. Probably for the same
reason - the russian 25% import duty.

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beaumartinez
Not in the UK—<http://www.apple.com/uk/iphone/specs.html>

~~~
jackvalentine
Are they just not advertising it in the UK though? It doesn't show up on the
Australian site either, but I was pretty sure Apple was the one company that
didn't do regional hardware variants.

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Neuromantic
ALSO: "Fingerprint-resistant oleophobic coating on front and back" WHAATTTTT

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hackermom
Related: the two first Galileo satellites
(<http://en.wikipedia.org/wiki/Galileo_(satellite_navigation)>) will be
launched tomorrow. The claimed precision of the free-for-all service is as
granular as 1 meter, with the military/commercial service claiming to reach
centimeter precision. I wonder when this shows up in smartphones.

~~~
ConstantineXVI
Wonder how feasible it would be to have a single GPS+GLONASS+Galileo chip that
automatically feeds you the service(s) with the best signal; without murdering
your battery?

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mdasen
<http://en.wikipedia.org/wiki/GLONASS#Accuracy>

There are already chips that combine the results from GPS and GLONASS. Because
it moves from 31 satellites to about 50, time to get a fix is improved (since
it might see 4 GPS satellites and 2 GLONASS ones more easily) and accuracy is
better.

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lhnn
I don't see a reference to GLONASS in the sub's page.

Edit: It angers me that high-ranking users abuse their priviledge to downvote.
I'm making a legitimate point here; I don't see "GLONASS" or any reference to
alternative GPS in that page.

On Reddit, someone suggested that TIL links to Wikipedia should point to the
specific information, not the whole article. It got >1000 upvotes. When I
point out that there is no obvious link to the claim made in this submission,
someone rates my comment as useless.

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AdamTReineke
Ctrl+F -> GLONASS. It's there.

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lhnn
Assisted GPS

Digital compass

Wi-Fi

Cellular

I did a CTRL-F on GLONASS and no match is found. I said I did this in my
edit... I'd take a screenshot, but I'm at work.

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maaku
Where do you live? It's probably GPS-only for your region.

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randomdata
No sign of it on the Canadian website. Now you've got me curious if the
Canadian version of the phone has it disabled or something, because its
presence would really help me with an app I am working on.

