Re: useing a tablet as a chart plotter.
GPS in iPhone or Ipad?
Spoiler :: Ability to talk to cell tower => it has a real GPS
Story version. . . .
It's a Really Good Question.
I bought my first iPhone in 2008 and I had some amazing digital experiences using it before/during /after the Great Chesapeake Bay Schooner Race (s/v Rosemary Ruth) that year where we started and finished the trip in NYC. (Note: Captain Richard Hudson has since sailed to Brasil, Baffin Island, Greenland and then Circumnavigated N&S America via NW passage, Chilean inner passage , the South Shetlands in Antarctica and after S. Africa and Namibia he single handed St. Helena to Norfolk USA when there were some crew transportation problems. Whew!)
Fast forward a decade . . . sprinkle on a couple wrinkles and 3 or 4 gray hairs . . . and today I have many old iDevices laying around and they all are the type that can talk to a cell tower and get an internet connection, which means they all have built in GPS.
Note that the WiFi ONLY iDevices do NOT have GPS built in.
Most of the more than a handful of GPS iDevices are NOT currently registered with a carrier (ATT, Verison, Sprint, T-Mobil, TelCel, etc) and so can only be used with WiFi internet. However they all still function perfectly well as mobile chart plotters. In fact we will have one or more of our boats chartering starting next summer and will be using the old iDevices running apps such iNavX, SEAiq Open, etc as extra throw away chart plotters. Some issues that the OLD Apple iDevices have is, they use an older version of IOS and that they must be registered with an Apple account in order to own/purchase/install Apps. That is unless one JailBreaks the device. Jailbreaking iDevices is something I have no experience with but seems very doable, especially if one is dealing with older devices with a vintage version of Apples IOS operating system, which is currently at version 10. A number of our old iDevices are stuck at IOS 5 or greater but still function, albeit the apps installed are older versions that will function with the older operating system.
( http://ipadpilotnews.com/2015/12/ipad-real-gps/ )
Does the iPad have a “real GPS” in it? December 28, 2015
Google the phrase “does the iPad have a GPS” and prepare to be overwhelmed. More than five years after the iPad was introduced, lots of people are still confused about whether the tablet actually has a GPS in it. And if it does have a GPS, is it a “real” one? Let’s bust some myths and settle the issue once and for all.
iPad with built-in GPS
Is it a “real” GPS?
First, some simple facts. Every iPad ever made has both WiFi and Bluetooth, two wireless technologies for connecting to nearby devices (in the case of Bluetooth) and the internet (in the case of WiFi). The only additional option is to add cellular service, originally called 3G and now called LTE for the latest models. This cellular option allows the iPad to connect to the internet anywhere your cell phone works, so if you want to check your email while driving down the interstate, you can do that (but it won’t work in flight).
There’s more to the story, though. In addition to the cellular radio, the 3G/LTE models of the iPad also have a built-in GPS receiver. Apple calls this “assisted GPS,” which is probably where the confusion comes in. By assisted GPS, Apple means that the GPS receiver in the iPad can use nearby cell towers to provide a faster position lock (what engineers call “time to first fix”). Instead of starting up cold and searching for satellites, which can take up to a few minutes in some cases, the iPad knows right where to look. With a hot start like this, your iPad can find its position in just seconds.
This is a handy feature if you’re trying to find your location on a map, especially if you’re in a big city where buildings can block GPS reception. But it’s important to note that the iPad does not require the cellular connection. In fact, you can purchase a 3G/LTE iPad, never sign up for service with Verizon or AT&T and still get very good GPS performance. If you want to test this, go to the Settings app and turn off Cellular Data, Bluetooth and WiFi. Even with all of its wireless radios off, the iPad will still show your position on ForeFlight or Garmin Pilot (again, assuming it’s a 3G/LTE model). And once you’re flying, your iPad will have an excellent view of the sky and should maintain good GPS accuracy.
So “assisted GPS,” far from being a cheap version of GPS or an Apple marketing line, is actually a good thing. By using all the other sensors on the iPad, the GPS performance is improved. Make no mistake: the 3G/LTE iPad has a real GPS built-in.
This is the first lesson ye should learn: There is so much good in the worst of us, and so much bad in the best of us, it doesn't behoove any of us to speak evil of the rest of us.