iOS8 series GPS accuracy *****

Give Feedback to Apple.

pete

iOS does not only use GPS for location services. You probably know this already, but here is an overview of how the system works…

https://en.wikipedia.org/wiki/Assisted_GPS

Please note the final sentence at the end of the first paragraph of the description …

A GPS unit may require as long as 12.5 minutes (the time needed to download the GPS almanac and ephemerides) to resolve the problem and be able to provide a correct location.

If you want an accurate GPS device you should use a dedicated device, some can be paired to iOS. iOS is inefficient compared to dedicated devices (see how much battery you get running iOS mapping all day). iOS can lose GPS when indoors or inside a car etc.

iOS will fall back to less accurate methods (cellular, wifi based locations, even Bluetooth) when it has lost GPS signal or an app has not requested fine grained accuracy.

You can use this info to get the best out of your device - wait around for it to become accurate, launch Photos app before you need it or run an app that requests accurate locations constantly. I think it is better for you to know the limitations & select an appropriate tool for the job.

Pohka wrote:

TThanks Pete, didn't see their feedback piece. Appreciate the link.

Sorry Drew, you loose. First, they do have GPS receivers in them (or so Apple has claimed).

Drew did not say that iOS devices didn't have GPS receivers. He said, "iOS does not only use GPS for location services" (emphasis mine).

I would agree that some of the rest of his post is a bit confusing. Any GPS device, not just an iPhone, is likely to lose GPS signal inside a building or under heavy tree cover.

I'm getting, generally, excellent GPS accuracy, 15 feet or better when I'm outside, on my iPhone 6 running iOS 8.4.

Pohka wrote:

TThanks Pete, didn't see their feedback piece. Appreciate the link.

Sorry Drew, you loose. First, they do have GPS receivers in them (or so Apple has claimed). Even if not, cell towers do receive GPS signal (part of the reason cellular technology works is the excellent time GPS provides). If nothing else, they're broadcasting their position continually and your iPhone is able to triangulate using that (the more towers the more accuracy, same with GPS, the more satellites you see the better your accuracy to some degree)! same is true for wifi on the accuracy component. The Almanac is used by a true GPS receiver to know the position of the satellites. Next, I said I was using a Bad Elf (as well as a Magellan). Bad Elf is an Apple approved external GPS device, btw, even with it on and wifi on I was getting the error until I turned off wiki. Last item, I said I noticed a delta when the OS changed. My iPhone 5 gave great accuracy prior to recent updates.

1. The word is lose, loose means something else entirely. I posted here to try to help you understand, maybe I did 'lose' in that regard, but your lack of reading comprehension is not my fault or my problem.
2. I never said they don't have GPS, please read my post again, it doesn't say what you think it said.
3. I didn't deny it may have changed recently - Apple are constantly changing the OS. I simply the tried to explain they use a combination of sources to get a rough fix (in the 12.5 minutes that it can take to get a fix from GPS satellites). With assisted GPS patience & understanding can help you get better results. If you don't care to learn how it works that is fine.

Meg, thanks for reading what I actually wrote. The reason iPhones lose GPS indoors before a dedicated device is because it is a general purpose device. Dedicated GPS devices have antennas, amplifiers and processors designed to keep track of weak GPS signals. iOS has multiple antennas tuned to several frequencies (WiFi, Cellular, GPS, Bluetooth are on different parts of the spectrum). iOS is designed to use all of them instead of focusing on one, it also corrects via software, which changes.

Pohka, if you want to troubleshoot your problem, understanding will help. If you want to rant at how terrible Apple (and I am by proxy), tell the feedback page.

Drew Reece wrote:

Meg, thanks for reading what I actually wrote. The reason iPhones lose GPS indoors before a dedicated device is because it is a general purpose device. Dedicated GPS devices have antennas, amplifiers and processors designed to keep track of weak GPS signals. iOS has multiple antennas tuned to several frequencies (WiFi, Cellular, GPS, Bluetooth are on different parts of the spectrum). iOS is designed to use all of them instead of focusing on one, it also corrects via software, which changes.

That's a good point. However, most dedicated GPS devices don't also have the ability to use Cellular and Wifi (the assisted GPS you mentioned). My personal experience is that it's something of a wash. My Garmin handheld unit doesn't seem to do appreciably better than my phone.

Pohka, if you want to troubleshoot your problem, understanding will help. If you want to rant at how terrible Apple (and I am by proxy), tell the feedback page.

On that we are 100% in agreement. 🙂

Pohka wrote:

HI Meg,

You say you're getting 15 feet, what's you method of assessing

I look at where the phone says I am on Maps when I am in a known location. As Maps will even show the building on the street, I can generally even see if it locates me in the correct part of the building. The blue dot will shift position if I go from one side of the building to the other. If the blue dot is where I know I am, I figure the phone is pretty accurate. I tend to check this a couple of times a day as I record my location using an automatic journaling app.

I just dug out my Garmin handheld. After waiting 10 minutes for it to get a GPS lock, going inside to get my glasses so that I could see the screen and then getting the coordinates as the map on the Garmin wasn't good enough to tell by eye how accurate it was, I determined that the coordinates were the same.

I admit I don't use my phone for geocaching. It has been accurate for my running, driving directions and sticking pins on a map of where I've been.

Best of luck.