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Commercial Flights Are Experiencing 'Unthinkable' GPS Attacks and Nobody Knows What to Do (www.vice.com)

submitted 11 months ago by [email protected] to c/[email protected]

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Commercial Flights Are Experiencing 'Unthinkable' GPS Attacks and Nobody Knows What to Do::New "spoofing" attacks resulting in total navigation failure have been occurring above the Middle East for months, which is "highly significant" for airline safety.

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[–] [email protected] 9 points 11 months ago (1 children)

Yes. Most of commercial navigation systems rely on the IRUs as a primary source of position data, and they'll usually have 3 of them. VHF is used by the crew to confirm that the aircraft is on track by referencing VOR stations, though these are slowly being phased out due to GPS.

That being said, a single traditional IRU can have up to 2km of drift over a 2 hr flight (at which point it's removed from service and replaced). When used in combination with two other IRUs, the error is dramatically reduced. Traditional IRUs are gyroscopically mechanical in nature and do not talk to GPS.

Now, that being said, the new standard is called an ADIRU (ADvanced IRU), which ties in with GPS and features laser gyros. They're extremely accurate and have essentially zero drift, plus multiple redundant components within each unit.

[–] [email protected] 7 points 11 months ago* (last edited 11 months ago)

If anyone is really curious about how INS works https://en.m.wikipedia.org/wiki/Inertial_navigation_system

Also this Air Force training audio REALLY clears the subject up: https://youtu.be/VUrMuc-ULmM

The Missile Knows Where It Is

Transcription for the audio is as follows:

"The missile knows where it is at all times. It knows this because it knows where it isn't. By subtracting where it is from where it isn't, or where it isn't from where it is (whichever is greater), it obtains a difference, or deviation. The guidance subsystem uses deviations to generate corrective commands to drive the missile from a position where it is to a position where it isn't, and arriving at a position where it wasn't, it now is. Consequently, the position where it is, is now the position that it wasn't, and it follows that the position that it was, is now the position that it isn't.

In the event that the position that it is in is not the position that it wasn't, the system has acquired a variation, the variation being the difference between where the missile is, and where it wasn't. If variation is considered to be a significant factor, it too may be corrected by the GEA. However, the missile must also know where it was.

The missile guidance computer scenario works as follows. Because a variation has modified some of the information the missile has obtained, it is not sure just where it is. However, it is sure where it isn't, within reason, and it knows where it was. It now subtracts where it should be from where it wasn't, or vice-versa, and by differentiating this from the algebraic sum of where it shouldn't be, and where it was, it is able to obtain the deviation and its variation, which is called error."