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发表于 15-10-2010 13:37:56|来自:北京海淀
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ipad没有gps芯片。。。。
我爱川妹 发表于 15-10-2010 11:56
Found some answer:
iPad Specs are clear - it's got GPS
Location
Wi-Fi
Digital compass
Assisted GPS (Wi-Fi + 3G model)
Cellular (Wi-Fi + 3G model)
This lists 4 technologies for location information.
1. Using the WiFi data to get position (Not as accurate but works
inside)
2. Digital Compass (Provides direction information that GPS can't)
3. Assisted GPS (GPS is GPS, assisted means it combines other data
with the GPS)
4. Cellular (Not very accurate method using GSM towers)
So the iPad does have GPS but only on the 3G model.
There is no such thing as fake GPS - if they say GPS they have to mean
it, it is a defined technology using the Global Positioning System, it is
not some sort of way of saying it can work out where it is.
Anything that does not use the Global Positioning System is not GPS,
A-GPS is also defined as using GPS plus other data. This cannot mean
pretending to have GPS.
This is why Apple correctly lists 4 different technologies. So even if the
A-GPS system cannot find a position, the WiFi based method might
and the Cellular triangulation method might.
As inaccurate as the other methods are, the GPS system is severely
limited also. GPS is accurate if it has a signal, and often it doesn't,
such as indoors or in the back of a car, in which case GPS will just be
unable to give you anything, and you had better hope for Cellular or
WiFi signals.
All models will use data from the Wi-Fi and Compass to work out
where they are.
The 3G model will use data from GPS and from 3 other methods to
work out where they are.
All models will know which way is North - which GPS cannot provide.
Any ambiguity is in the minds of those who wish to pretend that
Apple has failed and do not have the skills to read a technical
document properly.
I think the logic is that if you buy a Wi-Fi only model you want the
cheaper option, and probably intend to use this in one location, so
why pay for a GPS chipset to know the device is where it always is.
If you buy an iPad to take around you probably need the 3G to get on
the net so the GPS is included.
This makes some sense as it saves having 3 ranges. It also makes
sense from a build point of view, the GPS chipset and antenna is
probably on the radio card.
And from a battery life point of view the lack of chipset in the WiFi will
reduce the power consumption.
Also if you buy one of these to use within a building then GPS is
probably not going to work anyway, so why add a radio pack that will
never see a signal?
I do not know the insides of the iPhone but if it is like many GSM
phones there is one board for the CPU etc and one for the Radio pack,
if this is the case then Apple could streamline the product designs and
use the same radio card in the iPad that they use in the iPhone, this
would save a lot of messing around for them and for the consumer in
case of service.
Yet again a whole lot of ignorant people going wild trying to knock down
Apple cause they don't have a clue what they are talking about, and
generally trying to brand Apple users as ignorant cultists, when they are
the ones who need deprogramming and a decent IT education. |
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