Apple issues statement on iOS location controversy, says fix is coming - Page 4

Yes, once position has been established, then it's "the more the merrier" for accuracy, but on a declining scale. Once you've got 6 or 7 sats identified, adding another two or three more doesn't improve the accuracy all that much. Perhaps from an estimated 12' down to 9-10'. But the accuracy of the gps location isn't the big variable. It's the quality of the maps the device uses. All maps used by consumer gps devices are rift with positional errors.

As for how many satellites are generally used for navigation, it's common for 8-11 satellites to be "found" by modern gps navigation devices within a few minutes at most.

The article says that eight are visible in the current system. So that must be the max.

I also use Navigon (and will use Navigon Europe on my trip next month). I also did not opt for the extra fee for traffic "info", for the same reasons, and I've heard it's not quite ready for prime time. Not sure where TomTom and Navigon get their traffic data, but I know many companies are working (and Apple also, as announced) on a better way to gauge traffic. If it were really accurate, gathering speed and location info on thousands of cars, then I would feel it would really be useful for urban commuters, since you can only have so many Eye In The Sky helicopters, or people analyzing cams around the city, to be that confident that if you choose a different route to work/school, etc, you will really save time, gas, and hassle.

If the number of discovered satellites drops to fewer than 4 you will lose gps fix. At least four are required to maintain positional estimates.

We need to know whether these apps are allowed to keep any of this info. I tend to doubt it, as they have to ask each time. I don't remember any app stating that they were keeping any of the info, except for mapping apps such as my GPS app. And we're expressly telling them to do so each time.

That is how my Garmin works. I see each satellite as it is detected and slowly locked. As soon as I have three it displays my location on the map. This experience along with the documentation included with the device lead be to believe that only three satellites were required. I did notice that it sometimes would display the elevation incorrectly. I first noticed this when descending a steep route to sea level. Now I understand that it must be reusing my last known elevation in lieu of a fourth satellite.

Even when you have accurate flow data, if there's a delay of even 5 minutes in delivering that info to your mobile device, the traffic data may no longer be reliable, depending on the cause of the reported traffic issues.

This is what I've been saying, and you've been telling me no to. Though, as only eight satellites are line of horizon at any one time, I wonder how the receiver sees more than that number.

I assume that's only if you're moving though. Theres too much evidence that shows that only three will locate you accurately, at least to horizontal position without elevation data. As the article shows, the assumption is that you are on the earth's surface if you are below 11 miles.

In all fairness the “abuse," which I recall was simply disagreeing with you, wasn’t against you requesting Apple respond to the issue or making the changes they said they would make on these bugs — which I would qualify more as parochial coding not a bug — but with other aspects of your hypothesis.

Once a device has acquired its location and it remains in contact with the satellites, location updates are very fast. All military equipment simply will stay connected constantly (except submarines that is).

As far as I remember assisted-GPS provides you with the precise position of the satellites your GPS device is communicating with (and indirectly thus which of the satellites are ones that should be communicated with because they are in best position). The data connection to the satellites is fairly slow (hey it is a pretty old system), the main data sent from the satellites is very precise time signals, as the travel time of the signal depends on the distance between you and each satellite, you can from the travel time and the position of the satellites calculate your position. The satellites also send their position but receiving that takes longer than the pure time signal.

For those that really and truly want to understand what your GPS device is telling you and how it works, pay a visit to GPSReview.net

A friendly, active and patient forum with exceptional knowledgeable members and moderators. There's already been too many wrong assumptions posted in this thread to take up more time from the original subject.

To MStone: Watch more closely the next time your gps boots up. You won't have a lock at three satellites. They lock in so quickly it's sometimes hard to catch. If the sat bar is solid it's locked. If hollow it's only found but not yet usable for navigation purposes.

To Mel: The article you're relying on is incorrect on several statements. Wander on over to GPSReview,net one day when you have time.

Encryption, there is an additional encrypted signal that contains more information which increases accuracy. The military has the key to decrypt it, you don't have it.

Wasn't it Engadget which had switched off their comments for a month, because they were getting so ridiculous?

I'd think that it would be fairly simple to write an app that people could voluntarily use to do precisely what you're suggesting. The trick would be writing it such that it didn't become a battery drain.

Opportunity!

Tin foil hat, anyone?

Yes, they will explicitly ask you every time you start them up. But Apple cannot tell apps to 'forget' any data, it can only reject apps that store data but do not make that clear to the user.

Calmer minds have noted that Franken's questions are totally appropriate from the viewpoint of the non geek world (i.e. most people.)
If this episode sheds light on the 24-hour homing device that most of us carry around, then its a good thing. People need to be conscious of the implications of technology... most aren't.

I'd like to see people also be reminded that the FastPass on their dash tracks them even more closely.

Yup....There is a huge difference.

These are locally stored files (on your computer) which after the bug causing the data to be saved for 1 year, uptil 7 years, would probably have increased in size by a few mb. Its the same data, just that the automatic cache flushing algorithm was wrong.

OTOH, Google was picking up data that was completely irrelevant, and they didn't need in the first place. They specifically had to write code for it, it being something they didn't need, and collecting of which is illegal.

I’m still and will likely always be amazed that we have the technology in our lifetime to get such accurate data.

• 1903 — First powered flight
• 1953 — First supersonic flight
• 1957 — First human-made object orbits Earth
• 1959 — First human-made object lands on Moon
• 1961 — First manned mission to space
• 1962 — First communications satellite to direct relay TV broadcasts
• 1964 — First geostationary satellite
• 1969 — First manned mission to moon
• 1978 — First GPS satellite
• 1997 — First time Skynet becomes self aware
• 2001 — First time we make contact

(Apologies to JeffDM for all these FIRST posts)

I was amazed that my iPad2 gave accurate altitude data on my plane trip to Vegas last weekend. The Foreflight App for pilots was within 200 feet of accuracy on the trip, which is much better than my old Garmin unit, which was accurate to around 500 feet. Having dedicated GPS apps has made my plane and auto trips enjoyable, without having to worry about cell tower or wifi coverage.

It's a no-win for Apple. The Apple-haters, trolls, and other whiners will do anything to stamp an "Apple is Evil" moniker on Apple's image.

I give it one more day max before a few of the conspiracy theorists from a few threads ago (They are easy to spot) backtrack on their accusations and try blowing enough smoke in the hopes that no one will call them out for spouting their mouths off before knowing all the facts.

I gave it a month before this media-frenzy was forgotten. I was wrong. It seems it will happen much sooner than that.

The sad part is that if you're a smartphone-owning individual (regardless of OS affiliation) that enjoys all the functionality and experience of its near-instantaneous abilities, you're already being a hypocrite if you cried foul on this subject. In the subject of map coordinates, if on-demand, at the second determination of your exact location had to be done real-time, you'd blow a gasket as to why it was taking so long to load. There's a reason all these databases exist, yet as usual the whiners here fail to look at the long-term reasons and simply decide to be lazy and point fingers at some Big-Brother conspiracy.

The reality is, any individual connected to the grid, Internet, by alien brain-implants can be tracked in many other ways. The guys in the black suits flying in the unmarked back helicopters don't need to hijack your phone to do it. Unless you decide to forgo technology and live the solitary Ted kaczynski hermit lifestyle and live in the woods, get over it.

They grounded their posters? Next time are they going to pull this internet over if they dont behave?

The number visible varies. 8 is a targeted minimum in the system design. It does not represent a maximum. 10 is not uncommon, especially airborne or at high points. I've seen 11 on occasion. 12 is theoretically possible. That is one reason why modern receivers are 12 channel or more. I think this discussion is getting lost in the weeds.

So you are saying that this Garmin document is incorrect?

http://www8.garmin.com/manuals/eTrex_OwnersManual.pdf

page 41, last paragraph.

It really depends on the unit. Most consumer units will continue to report position with 3, often indicated on the display as a 2-D fix (rather than 3-D). That is also an indication that it is using a constant elevation assumption to determine location.

One should always read the entire paragraph. It indicates what has been discussed in this thread. Note the Earth is spherical, not flat.

If you want to be pedantic you can say on satellite can determine your position, albeit within a very generalized location that is far to great to be useful to the user unless they only need to determine which continent or planet they reside.

Fandroids and general Apple haters are out in force all over the 'net.

They're starting to look like 'birthers.'

Not at all. You're simply misunderstanding what is being said. Or not said actually. The section you reference doesn't say only three satellites are necessary for a 'fix".

Your eTrex, or nuvi, Magellan or TomTom or whatever won't give you a positional fix until it has four satellites locked. That's just the way it works.

You mean Al Franken?

Speaking of which, how come Steve Jobs won't produce a birth certificate? I mean, do we even know that he was born? He could've been conjured by a dark mage.

At least some of the Garmin units will give you a 2-D lock from a cold start. I don't know what assumptions may be made in that case - nominal sea level or elevation lookup.

Fine, I've given you three very credible reference documents that contradict your claim, and you have provided a forum with some nice people. I guess I usually have several satellites so I'm good. Thanks for your comments.

Why does this article, which includes an explicit statement from Apple that says, in partial response to question #3 (Why is my iPhone logging my location?):

"The iPhone is not logging your location. Rather, its maintaining a database of Wi-Fi hotspots and cell towers around your current location, some of which may be located more than one hundred miles away from your iPhone, to help your iPhone rapidly and accurately calculate its location when requested."

... end with this sentence,

"[...] Though the file created by iOS 4 is not sent to Apple or anyone else, it keeps a detailed list of locations a user has been (italics mine) and is saved unencrypted on the phone, as well as in iTunes backups."

... which appears to have been written by somebody who did not read the Apple response?

In fact, according to the response from Apple, it is not a "detailed list of locations a user has been." Too much of the dialog about this issue has been excessively sloppy about the facts.

Im gonna say youve been using it the whole time.

But if you really turned it off I say leave it off and wipe the NAND until they issue a fix. In the mean time you should totally wrap it tinfoil, but in a lead-lined box and bury in the backyard.



Maybe he was created by Xerox PARC. The original gooey as he was actually made from goo.

Notice how all of these achievements accelerated after Megatron was found and Hoover Dam was built around him

On serious note, I find it amazing how all of these achievements happened in less than 100 years given that man have been around for tens of thousands of years.

More like lead-lined

Youre on a tech site citing layman definitions to Gatorguys (and mine) technical definitions.

I hardly consider two Garmin owners manuals and Wikipedia as layman definitions. They may be wrong and you may be right but surely you can understand why someone might trust their information before some unknown anonymous Internet dudes when there is a contradiction.

Our ancestors we lazier than us.