Do cameras record compass direction or orientation in photo metadata, and can they track position better than GPS?

Asked 5/16/2011

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I’m trying to understand what camera sensors can record for each shot. Some devices have gyroscopes, accelerometers, or a digital compass, and some cameras also have GPS.

Can a camera store the direction it was pointing (for example, compass heading) in image metadata, in addition to GPS location? Is there a standard way this is tagged?

Also, do any cameras offer position tracking that works better than GPS, such as indoors or when GPS is unavailable?

My goal is to see whether this kind of data could help align or stitch photos when the scene doesn’t have enough visual detail for normal software to match reliably.

Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0

Photography Stack Exchange contributor

15y ago

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The gyroscope in an iPhone doesn't actually let you track the direction the camera was facing at the time of a shot. All it does it track motion--it has no frame of reference to determine what point of the compass the camera is actually facing.

The "digital compass" in the iPhone 3G S onwards can give some idea of that, except that it's designed to be used when the iPhone is more or less flat. It would thus require a mirror to be fitted to the camera lens to be useful, and in any case compass data isn't included in the EXIF info. I would expect that any camera providing directional capabilities would be using an equivalent "digital compass" using a magnetometer.

Originally by user5266. Source · Licensed CC BY-SA 4.0

user5266

15y ago

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A gyroscope alone does not tell you which compass direction a camera was facing. It measures motion/rotation, but without an external reference it cannot determine absolute heading.

To record pointing direction, a camera would need a compass-like sensor (magnetometer), not just a gyro. Some GPS-equipped cameras can also record orientation data, but this is not universal, and compass/heading data is not something you should assume every camera writes into EXIF.

Orientation is more commonly recorded as camera rotation (portrait/landscape), often via accelerometers. That is different from compass direction.

For position, GPS is still the main reference. If you want tracking when GPS is unavailable, the next step is inertial navigation: combining accelerometers/gyros with the last known GPS fix. Some cameras have offered variants of this for limited indoor/dead-reckoning use, but it is not a true replacement for GPS and tends to drift over time.

So in short: some cameras can record orientation, a few may supplement GPS with inertial sensing, but absolute pointing direction and highly accurate non-GPS positional tracking are not standard camera features.

UniqueBot

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15y ago

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