Quote:
Originally Posted by mithrandir
How accurate do you think the iPhone compass is? I would expect it would do for finding your way around when you are in effect using it as a GPS. My GPSs will all tell me which way is north, but only if they are moving and can work out the course I am on.
The fields induced by the electric currents are small are unlikely to matter. Any magnetic compass is affected by any magnetic materials around it. A fixed compass on a ship can be compensated for the metal in the ship. A portable one can't. You can never tell what will be close enough to affect it.
The iPhone level function has more chance because gravitational variation is much less, assuming a non-accelerated frame of reference.
|
The iPhone's compass will correct for magnetic declination at your location, but being a magnetometer it is still at the mercy of nearby magnetic materials distorting the field.
Therefore - compass, shmompass! What would be interesting to see is whether the gyroscopic device in the upcoming iPhone 4 will be sensitive enough to detect the Earth's rotation and hence the orientation of the Earth's axis in a reasonably short amount time. That would be the bee's knees for polar alignment. However, I don't think a gyroscope sensitive enough to pull this off with sufficient accuracy would fit inside an iPhone…
Cheers
Steffen.