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OT: Pilot Question

In poking around for info on navigational equipment, my search for "artificial horizon" side tracked me into the aviation world. And then into the Android/iPhone app world.

It appears as though there are a few "artificial horizon" or attitude indicator applications for these gizmos that use the tilt sensors (accelerometers IIRC) and display an attitude indicator similar to that of a aircraft.

What's got me wondering: Tilt sensors would measure the vector sum of gravity plus the centrifugal acceleration caused by a turn. So for a well coordinated turn, the phone app would point toward a different 'down' that an actual gyroscopic AI would show. Worse yet, there appeared to be a few 'pilot testimonials' about how handy these gadgets are.

Do iPhones actually have a true gyroscope (I sort of doubt it). If not, how would they separate attitude from centrifugal force? Or is this just a useless* toy?

*Dangerous too, if someone is depending on it as backup instrumentation. 
--
Paul Hovnanian     mailto:Paul@Hovnanian.com
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43rd Law of Computing:
Anything that can go wr
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Reply to
Paul Hovnanian P.E.
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They have differential sensors in different locations, don't they? Three defines a plane, so they could sense moments with three, and therefore rotational as well as linear acceleration. Either that, or they have gyros that do the same thing.

At any rate (pun?), they're probably semiconductor accelerometers/gyros, which are drifty. So they'd be okay in the short term, dubious in a pinch, and quite bad in the long term without something more stable to keep them centered.

Tim

-- Deep Friar: a very philosophical monk. Website:

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Reply to
Tim Williams

Yes, the latest generation does:

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Best regards, Spehro Pefhany

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"it's the network..."                          "The Journey is the reward"
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Reply to
Spehro Pefhany

Look into RC helicopters. Some of them use a sort of infra-red camera to look at the horizon. Only works in a field.

Reply to
a7yvm109gf5d1

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Interesting. And there, toward the bottom of the page is a screenshot of exactly what I was thinking about.

I still don't know if I'd trust an iPhone to keep my plane upright.

--
Paul Hovnanian  paul@hovnanian.com
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Have gnu, will travel.
Reply to
Paul Hovnanian P.E.

Mikrokopter seems to have the required gear pretty much figured out, I think.

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It is an open source project so you can sniff around and see what they use.

I found it impressive that their gear can stay aloft in one spot with

10kts of wind. Youtube has quite a few videos.

No affiliation.

Regards Werner Dahn

Reply to
Werner

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