Quote:
Originally Posted by kovidgoyal
A good point, I wonder why cell phones don't affect their own GPS receivers, or for that matter GPS receivers in car navigation systems.
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They might, not really a big deal though, if you look at a track of most GPSs you can buy, you will see points where there is a straight line jump from one position to the next, generally this is an area where the GPS isn't tracking, and doesn't get a point or so. Not a big deal on your cell phone, car navigation, hiking, etc, and generally within the specs for a consumer GPS, take the Magellan Maestro 4700, it's specs for resolution "GPS Accuracy 3-5 meters", which is much better than used to be available with SA enabled.
Also, the most a car or cell phone is good for is as a navigational aid, not as vehicle control, get a glitch, lost signal, etc, no big deal.
Now, wrt trying to harden a plane to consumer devices, it is almost an impossible task. You would have to get every conceivable device, and test those in all combinations with all combinations of planes to prove there can't be a problem (probably add in the mix every possible location in the plane for each device on each plane). Everytime a product is introduced or update, or a new plane is introduced, or something is changed on a plane, you would need to re-do these. Worst scenario is a new consumer device introduced or a device changed, since all combinations would need to be tried. All devices would need to be tested until the last one fell out of use.
That would be the only way to prove your device can't cause problems.
The other issue, planes should be designed for this type of thing. I agree, they should be, but currently they aren't, and the fleet is very unlikely to undergo an immediate upgrade to fully shielded vehicles. Devices should also be designed to emit only those radiations meant to be emitted (ie on an e-reader, light and the specific radio waves when 3G or WiFi is on), but they won't, manufacturers will do the least required by law to save money.
I have seen a lot of things on circuit boards that become antenna to a number of different frequencies (do you know how many different frequencies your e-reader is emitting), and to control those to the point of no chance of a problem is a daunting task, and an expensive one, are you willing to pay 25% or more the cost of a device so you might be able to use it during take off and landings of an airplane? Is everyone willing to bear that cost?
--Carl