Does iPad 2 WiFi Really Have No GPS???
iOS 4
iOS 4
Now, what is the signal flow for A-GPS? I'm thinking that the DGPS ground station transmits not only the GPS error information but also its own location. >This is received by the cell towers and, after signal conversion, is retransmitted out to the cell phones and similar devices
As soon as I turn my device on, it takes the A-GPS information to use as a "ballpark" estimate of its own location. That, in turn, makes it easier to locate the visible satellites. Close?
According to several web sources, the iPhone and iPad do indeed support cell tower triangulation, or at least they did.
Michael Black wrote:
To be fair, the NASA article simple states:
"Assisted-GPS (A-GPS) data – provides data and information about the GPS orbit and clock states that allow cellular phones to pinpoint their location on phone map applications and when making emergency 911 calls"
It does not say that aGPS is a feature of the DGPS system. aGPS was developed by communications companies and (Lucent and Qualcomm being amongst the biggest players in it's development, as well as companies rapidly bought up by Qualcomm). aGPS is a feature of the cellular carrier network, not the GPS infrastructure per se. The "assisted" in aGPS has meant a number of features implemented over the years since the early 2000's that improve the speed and accuracy of a location fix.
I'm getting a headache.
Hersco wrote:
The real question for me is: If I buy a Wi-Fi-only iPad (no 3G) and tether it to my iPhone to gain 3G access, will the iPad use the GPS on the iPhone for the apps that requir Location Services?
they use technology from SkyHook (or at least they used to)
Does iPad 2 WiFi Really Have No GPS???