Accuracy of iPhone compass - can it be calibrated?

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Level 1

9 points

Accuracy of iPhone compass - can it be calibrated?

There’s a basic test you can do to see how accurate the compass is. Please anyone say if you don’t think it’s valid.

In Google maps, get a close-up satellite picture of the building you’re in, using the compass feature so that the image aligns north as you turn the iphone.

Then place the edge of the phone against one of the walls of the building. The image of the building on the phone should appear flush or square to the wall as appropriate. Repeat the experiment in different buildings to allow for interference.

My compass seems to be about 20 degrees out. It’s not that important, but I’d like to be able to calibrate it properly. Is this possible?

iPhone 4

Posted on Jul 30, 2012 5:42 AM

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Answer 1

tonefox

Level 6

9,368 points

Jul 30, 2012 6:26 AM in response to Batcow

From the User Guide:

"You need to calibrate the compass the first time you use it, and occasionally after that. iPhone alerts you if calibration is needed.

Calibrate the internal compass: Wave iPhone in a figure eight."

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Answer 2

Oct 20, 2012 12:26 PM in response to Batcow

Batcow, one thing to include in your calculation is the magnetic declination. Depending in your location true north on a map is different than magnetic north. A map will show true north but a compass will show magnetic north. You can lookup the difference for your location. Having said that based on the idea that my house is orientated perfectly north/south which may not be perfectly accurate (it appears very close on google maps) my iPhone 5 compass appears to be 8 degrees off. It measures north 8 degrees off instead of the 16 that it should be.

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Answer 3

Batcow Author

Level 1

9 points

Jul 30, 2012 6:31 AM in response to tonefox

Thanks, but I should have mentioned that I already tried that. It's as if the default setting of the compass is a bit out. I'll see if it sorts itself out with time, otherwise it's something I can live with.

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