Evidence of iPhone 6 Atmospheric Pressure Sensor Found in iOS 8

[kdarling]

No, I was not aware of the offset.

I think very few people are. The offset in the official equations drove me crazy until I was able to track down the more than sixty year old reason for it.

That's good stuff. I will try it out on some of my grizzled veteran pilot friends and see if they are aware of this. All these years we've been doing it wrong. I can now blame all of my worst landings on this terrible hidden discrepancy.

Ha! Yes, it's a perfectly scientific excuse for a hard landing

Anyway, the point such as it is: measuring barometric pressure inside a building seems like a pretty dicey affair, especially a modern building without opening windows and an aggressive HVAC system. So I am thinking, anyway.

Oh boy, do I have a document for you. Good old Microsoft Research ran some tests with various smartphone sensors to see if they could repeatedly and accurately determine floor changes (and method of floor change - stairs, escalator, elevator).

They concluded that it was quite accurate at those things, but it could be difficult to determine an exact floor without outside information. See paper here.

And if you need any more E-6Bs...

You, sir, get extra points for spelling it correctly. The original Army version was the E-6B. Later makers corrupted it to be E6-B, etc.

In fact, I wrote the original detailed history of the E-6B and its Popular Culture References that you see in Wikipedia.

Long lost to history, I was able to obtain from Philip Dalton's descendants copies of his personal letters, and finally document the details of the E-6B timeline. (I even have a photo of the E-6A prototype!) Take a look if you get a chance. Thanks!

 

[Nigglesworth]

atmospheric pressure of my pocket

Can't wait to find out the atmospheric pressure of my pocket on hot summer day. Moist & steamy!

 

[kdarling]

Wow, if you've got a reference for that, I'd be keen to do some further reading. The ability to detect a one metre elevation change near sea level implies a resolution of about 10Pa, which I consider to be very impressive.

Here's the data sheet for the one used in... oh gosh, I forget, either the Xoom or the Galaxy Nexus... the STM LPS331AP.

Each one is calibrated at the factory, and has a relative accuracy of +/- 0.1 millibar, which is indeed 10 Pa as you said.

 

[aggri1]

Here's the data sheet for the one used in... oh gosh, I forget, either the Xoom or the Galaxy Nexus... the STM LPS331AP.

Each one is calibrated at the factory, and has a relative accuracy of +/- 0.1 millibar, which is indeed 10 Pa as you said.

Ah cheers; and yikes!

 

[Meow.]

This is the revolution of meteorology... Everyone can record a typhoon or hurricane’s pressure by their iPhone.

 

[pdaholic]

.

 

[macs4nw]

Wouldn't this be a more likely watch feature?

Remember the new iPhone and that rumored 'iWatch' are purportedly companion devices complementing one another, and for this particular purpose, it's immaterial in which one of the two devices the actual sensor(s) reside.

Could be just a space, or battery-life consideration.

 

[Aniseedvan]

I'm all for an atmospheric pressure sensor for independent (ie: no network req'd) altitude and barometer measurement, but would be concerned that it might prevent the new iPhone from being waterproof.

Not waterproofing the phone and having more outdoor-feeling focussed additions would seem at odds...

My Garmin fenix has this and is waterproof. Whether you can take it swimming seems up for endless debate on the Garmin forums but it's IPX7 rated irrespective, which would be great in a phone...

 

[Tarzanman]

What a novel idea.

 

[IJ Reilly]

I think very few people are. The offset in the official equations drove me crazy until I was able to track down the more than sixty year old reason for it.



Ha! Yes, it's a perfectly scientific excuse for a hard landing



Oh boy, do I have a document for you. Good old Microsoft Research ran some tests with various smartphone sensors to see if they could repeatedly and accurately determine floor changes (and method of floor change - stairs, escalator, elevator).

They concluded that it was quite accurate at those things, but it could be difficult to determine an exact floor without outside information. See paper here.



You, sir, get extra points for spelling it correctly. The original Army version was the E-6B. Later makers corrupted it to be E6-B, etc.

In fact, I wrote the original detailed history of the E-6B and its Popular Culture References that you see in Wikipedia.

Long lost to history, I was able to obtain from Philip Dalton's descendants copies of his personal letters, and finally document the details of the E-6B timeline. (I even have a photo of the E-6A prototype!) Take a look if you get a chance. Thanks!

Thanks for all this. I made a weak charge at the turgid prose of that paper but did not get far. I will try again when I'm feeling more courageous.

I have to admit, I probably lucked out on the correctly-positioned hyphen. The E-6B made multiple appearances on Star Trek? Surely that must have been an in-joke among the writers. Even in the '60s they could not have imagined that the slide rule would survive into the 22nd century!

Out of curiosity I pulled out the APR E6-B I purchased in my student pilot days. It is designated as E6-B9.

 

[kdarling]

The E-6B made multiple appearances on Star Trek? Surely that must have been an in-joke among the writers.

Yes! Supposedly it was because both Shatner and Nimoy were taking flying lessons at the time. Check these out, one small, one large:

Even in the '60s they could not have imagined that the slide rule would survive into the 22nd century!

That is funny! Star Trek came up with communicators, teleportation, tractor beams, warp drive, voice computers... but not pocket calculators!

A slide rule marked a brainy person during the 1960s, so Spock had to have one!

Thread related: to those who don't know, these slide rules are still backups in every pilot's bag. Among other things, they have special scales designed to calculate various air pressure values necessary for safe flight.

 

[tuartboy]

This may be a play for indoor mapping. In iOS 8, Core Location adds the ability to request information on what floor of a building the device is on. I believe it currently uses GPS and WiFi to do a rough estimate. This seems like the way they could make that a more reliable API for iPhone 6 devices.

 

[IJ Reilly]

That is funny! Star Trek came up with communicators, teleportation, tractor beams, warp drive, voice computers... but not pocket calculators!

A slide rule marked a brainy person during the 1960s, so Spock had to have one!

Thread related: to those who don't know, these slide rules are still backups in every pilot's bag. Among other things, they have special scales designed to calculate various air pressure values necessary for safe flight.

"Fascinating."

I was a huge fan of this show growing up, and have seen these episodes any number of times since, but I have no memory of Spock and his E6-B. I wonder how it was used to navigate the three dimensions of space? The wind vector calculator would be especially useful in setting course and heading in the vicinity of solar flares and Klingon disrupter beams.

I no longer carry my E6-B but I am thinking now I should stow one in the airplane and at least pretend to use it once in awhile. It is, after all, from the future!

 

[jlabute]

like a mood ring. lol

Will it 've a sensor to measure how much someone is sensually turn-on?

It would be a good iWatch application... have the screen color change as your mood changes.lol. Remember those rings from the 80's?

I don't think a temperature sensor is a great idea in a piece of handled electronics... it may not be accurate if it's been in your pocket or hand.

My 3 year old Galaxy Nexus has a barometer. Good for getting a relative indication of altitude as you're climbing a mountain, or gives you an idea of weather changing with a low pressure system coming in etc.

 

[likufanele]

Remember the new iPhone and that rumored 'iWatch' are purportedly companion devices complementing one another, and for this particular purpose, it's immaterial in which one of the two devices the actual sensor(s) reside.

Could be just a space, or battery-life consideration.

It is quite material to certain applications, such as a skydiving or paragliding altimeter. Putting the phone, and thus sensor, in a pocket of unknown permeability (many skydiving suit pockets are made of ZP, zero porosity fabric), would hinder the sensor's accuracy. The sensor would greatly benefit from being exposed to the ambient environment by being in the watch component.

This said, it's my feeling that the sensor will likely be on the phone, from a data transmission and master/slave point of view.

 

[acctman]

that's to track climbing stairs... step counter. my fitbit force watch has the same sensor