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Apple Q&A on gathering and use of location data (Apple Press Release)

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Re: Apple Q&A on gathering and use of location data (Apple Press Release)

#151

Post by bigiain »

morganw wrote: post #141
jrockway wrote: post #135

Earlier quoted context omitted.

Are you sure you've had 12 minutes with a clear view of the sky? Each GPS satellite carries the entire constellation's almanac. After downloading that (which is a 12.5 minute process), then you can download the ephemeris from each satellite, which takes 30 seconds. You need 4 satellites to get a location fix. The almanac is valid for 180 days, so you only need to wait 12 minutes once. From then on, you only need the…

> I can buy a $10 microchip that's the size of a dime that can do it. Give it electricity, wait 15 minutes, the location comes out the other side. How do you know when the 15 minutes starts, though? Dedicated GPSs tell you things like how many satellites they have in view and how accurate their fix is, but dumbed-down devices like to pretend location is magic. I'd hope they'd at least provide the gritty details throu…

You don't need to know "when it starts", it transmits in a loop, you need to collect ~12.5 minutes of that loop to get the entire almanac. (lousy software _might_ not understand unless it finds some particular preset mark in the loop, but it's not a GPS system architecture problem)

Re: Apple Q&A on gathering and use of location data (Apple Press Release)

#152

Post by nutjob123 »

nutjob123 wrote: post #90

A huge hole in this press release is how apps use location information. An app can easily log a user's location and send it anywhere along with whatever other data the app has access to.

Direct access to the user location is much more useful than a list of nearby wifi and cell towers.

Re: Apple Q&A on gathering and use of location data (Apple Press Release)

#153

Post by bigiain »

yaix wrote: post #120
DanielBMarkham wrote: post #82

The iPhone is not logging your location. Rather, it’s 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 Can Apple locate me based on my geo-tagged Wi-Fi hotspot and cell tower data? No. This data is sent to Apple in an ano…

>they are keeping a time-stamped list of nearby access points on my device, which effectively is a huge breadcrumb trail of everywhere Read again. They are not. Its not timestamped when "you" where there, but when some anonynous iPhone picked up that particular hotspot. It got then uploaded to Apple and subsequently downloaded onto your iPhone, so that your iPhone can find its location easier. Wasn't that kinda the o…

I'm pretty sure that's true. I'm going to try find some time this evening to animate the points out of the database from my phone to prove it to myself. I'm guessing the animation will show random segments of trails that anonymous iPhone users have travelled around my neighborhoods, but nothing I'll recognize as a trip I've made. (I'll blog about it at bigiain.com if I find anything interesting)

Re: Apple Q&A on gathering and use of location data (Apple Press Release)

#154

Post by somebear »

bigiain wrote: post #153
yaix wrote: post #120

Earlier quoted context omitted.

>they are keeping a time-stamped list of nearby access points on my device, which effectively is a huge breadcrumb trail of everywhere Read again. They are not. Its not timestamped when "you" where there, but when some anonynous iPhone picked up that particular hotspot. It got then uploaded to Apple and subsequently downloaded onto your iPhone, so that your iPhone can find its location easier. Wasn't that kinda the o…

I'm pretty sure that's true. I'm going to try find some time this evening to animate the points out of the database from my phone to prove it to myself. I'm guessing the animation will show random segments of trails that anonymous iPhone users have travelled around my neighborhoods, but nothing I'll recognize as a trip I've made. (I'll blog about it at bigiain.com if I find anything interesting)

Then you will write a very interesting, but somewhat misleading blog post, just like everyone else has written in the past few weeks.

The point is that the database on your phone is a subset of the greater (global) database mapping wifi and cell access points to location. The local database contains timestamps of when your phone downloaded the information. The global database only contains a list of access points and approximate locations of those access points.

That way, when your phone sees an access point it can look up in the database (locally or globally) and see if this access point has been pinpointed, if it has it will be another tool for your device to provide you with a proper location.

In other words: animating the points in your database will show the first time your phone downloaded information about a specific access point, which will give you a trail of your movements (to a certain extent limited by the factors mentioned above).

Re: Apple Q&A on gathering and use of location data (Apple Press Release)

#156

Post by tjogin »

jrockway wrote: post #135
sounddust wrote: post #130

Earlier quoted context omitted.

As far as I can tell, the iPhone cannot determine one's location solely from the GPS antenna. If you travel to a place where you haven't been before, location services simply won't work until you obtain internet connectivity for a few seconds. I don't know if this is because the iPhone's GPS functionality is crippled, or if it's a software limitation. I'd imagine that if you wanted to overcome this limitation, you'd…

Are you sure you've had 12 minutes with a clear view of the sky? Each GPS satellite carries the entire constellation's almanac. After downloading that (which is a 12.5 minute process), then you can download the ephemeris from each satellite, which takes 30 seconds. You need 4 satellites to get a location fix. The almanac is valid for 180 days, so you only need to wait 12 minutes once. From then on, you only need the…

Less than a minute is still a long time to wait for a position, and it requires visible satellites.

With the iPhone I get a decent location in seconds and a more accurate one in ten. Indoors.

Re: Apple Q&A on gathering and use of location data (Apple Press Release)

#157

Post by wowamit »

pieter wrote: post #32
ugh wrote: post #18

Earlier quoted context omitted.

Sure, that's why they say "anonymous". If they do not delete the IP address as soon as technically possible they are lying about the anonymous part. This is not about ability. This is about trust. They say the data is anonymous which means they are obligated to disregard the IP address and to not log it anywhere.

"This is not about ability" Sure it is. That's exactly what the following statement means: "Apple cannot identify the source of this data". How can you interpret that as anything else but their ability of identifying the source? The statement is obviously not true; if they were forced to, by a government agency for example, to track the location information from a user from that point on they COULD; saying they can't…

Out of context, that is what the statement would read. But with context I would read it as "Apple cannot identify the source of this data 'stored without IP addresses with us'"

Re: Apple Q&A on gathering and use of location data (Apple Press Release)

#158

Post by morganw »

bigiain wrote: post #151
morganw wrote: post #141

Earlier quoted context omitted.

> I can buy a $10 microchip that's the size of a dime that can do it. Give it electricity, wait 15 minutes, the location comes out the other side. How do you know when the 15 minutes starts, though? Dedicated GPSs tell you things like how many satellites they have in view and how accurate their fix is, but dumbed-down devices like to pretend location is magic. I'd hope they'd at least provide the gritty details throu…

You don't need to know "when it starts", it transmits in a loop, you need to collect ~12.5 minutes of that loop to get the entire almanac. (lousy software _might_ not understand unless it finds some particular preset mark in the loop, but it's not a GPS system architecture problem)

The user needs to know when the almanac is being received and when the whole thing is in when looking for a clear-view-of-sky spot to sit a while.

The best you can do with CoreLocation is set desiredAccuracy to kCLLocationAccuracyBest and wait for it to fall below 100 feet with no way to find out if it ever will.

Re: Apple Q&A on gathering and use of location data (Apple Press Release)

#159

Post by rbarooah »

lukeschlather wrote: post #132
rbarooah wrote: post #129

Earlier quoted context omitted.

So you want Apple to fail because you don't like what the other manufacturers are doing?

That's twisting my words a a bit isn't it? I don't like what Apple is doing. Other manufacturers imitate Apple. I want Apple to fail in the hopes that other manufacturers will stop imitating Apple.

I'm sure other manufacturers would stop imitating Apple if Apple failed.

But that's an incredibly negative view isn't it? By imitating Apple, the other manufacturers simply aren't contributing anything meaningful. It seems unlikely that Apple's failure would make them suddenly unleash a wealth of creativity and contribution on the world. If they had it, why wouldn't they be using it right now?

Wouldn't it be better for Apple to succeed, and the imitators fail? That way, we'd get the best of both worlds. Advancement of technology from Apple, and a clear marketplace signal that imitators are not wanted.

New companies and investors would who wanted to succeed would no longer be tempted to imitate but might actually innovate.

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