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Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

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Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#151

Post by jandrese »

tropo wrote: post #148
jandrese wrote: post #142

Earlier quoted context omitted.

In fact these do exist. I saw a demo a few years back from a company that tracked bogus GPS signals and how they could watch jammers drive around the streets of London all day long. These guys were doing it because they were tasked with keeping LTE towers synchronized and they did it with GPS time so they were building in resilience to their time sources by measuring the signal level and rejecting anything that came…

The GPS antenna on the LTE tower should only be picking up signals from the sky. Transmitters on trucks would need to reflect off of aircraft in order to cause trouble, which would greatly weaken the signal.

Yes the antenna pattern will attenuate the signal coming from the ground somewhat, but it also doesn't suffer from 182 dB of freespace attenuation like the real signal. It doesn't have to bounce off of an airplane either, the Earth has a layer of atmosphere around it that gets ionized by the sun and is also full of water vapor. We also don't have the ability to build perfect antennas, especially since it has to cover the entire sky (GPS antennas do not physically track the individual satellites).

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#152

Post by korethr »

redis_mlc wrote: post #146
jrockway wrote: post #67

A lot of comments seem to be about spoofing. Remember that there are multiple humans in the loop -- experienced pilots and experienced air traffic controllers -- and multiple levels of redundancy. Pilots have access to barometric altitude, radar altitude, traditional VHF navaids, TCAS-issued resolution advisories (based on directional antennas, not GPS)... in addition to GPS. Air traffic controllers have primary rada…

> Air traffic controllers have primary radar and secondary radar in addition to ADS-B information. No they don't. Most secondary (surveillance) radar in the US has been shut down already. The FAA has been busy shutting down basically anything that requires maintenance, and LORAN is gone too. I believe the whole point of ADS-B out was to shut down basically the rest. Source: commercially-rated pilot.

So then if everything goes to ADS-B and GPS, doesn't that create a potential single-point-of-failure scenario, as isn't the data that ADS-B sends out itself derived from GPS? Having all navigation information come from a single source strikes me as about a good idea as the single AoA sensor on the 737MAX.

I'd like to be wrong about this, but I'm not sure how I am. How am I potentially wrong about this?

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#153

Post by asteli »

echelon wrote: post #141
TkTech wrote: post #88

Earlier quoted context omitted.

And most major airports have systems like RFEye or AIRPORT-SHIELD. You would be _immediately_ pinpointed with a remarkable level of accuracy from 3-6 sensors. Especially near major metro areas, unintentional interference is a daily issue. These systems immediately triangulate sources of interference in a wide band. Or you have simpler systems like UMS100 that just do alerting and you send out an engineer with a wand…

Imagine an unlicensed drone emitting GPS radio signals. Just a small amount of sophistication and an attacker can do an incredible amount of harm.

If you live in Florida, you can go down to the pawn shop, buy a gun, drive over to the airport and start shooting at planes. Doesn't take much sophistication to cause a lot of harm.

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#154

Post by cbanek »

wrycoder wrote: post #149
redis_mlc wrote: post #146

Earlier quoted context omitted.

> Air traffic controllers have primary radar and secondary radar in addition to ADS-B information. No they don't. Most secondary (surveillance) radar in the US has been shut down already. The FAA has been busy shutting down basically anything that requires maintenance, and LORAN is gone too. I believe the whole point of ADS-B out was to shut down basically the rest. Source: commercially-rated pilot.

If you shut it all down and something catastrophic somehow goes wrong with GPS, it will be very difficult to get the thousands of planes in the air back onto runways.

Are they also getting rid of VOR for navigation?

https://en.wikipedia.org/wiki/VHF_omnidirectional_range

(Sorry, paywall is blocking me)

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#155

Post by sfifs »

LargoLasskhyfv wrote: post #124
zentiggr wrote: post #106

Earlier quoted context omitted.

I personally would volunteer to be on one of the teams in another van with directional antennas to triangulate your transmissions and shut down you ASAP. The fact that no one has ever truly tried that sort of poisoning of radio calls is more due to the tower and aircraft having a very well defined set of calls, so that the likelihood of false transmissions being able to cause havoc is minimized already. I agree with…

My question was of theoretical nature, i'm not up to mischief of that sort. Though i'm often thinking about the vulnerabilities of our technological society, and the (false) assumptions we have about that. Compare it with lock picking. Most are easily bumped, or not even bothering with that, the door kicked down, some window used instead, and so on. Now, when someone kicks your door down, that's getting noticed, soon…

Pulling these kinds of attacks - especially undetected - requires a certain level of intellect and education that should also be unaffected by things like substance abuse that hamper systematic planning. People with that level of capability almost always manage to create sufficiently comfortable life situations for themselves that they they lack motivation to do so.

Problems happen when either (1) technology to do harm becomes commoditized and freely available so less capable people can acquire and use (eg. Easy conversion of semi automatic to automatics, commoditized hacks for script kiddies) or (2) capable people feel they're been sufficiently wronged that they don't care about the consequences of revenge (pretty much all the really big headline terrorist actions)

Most intelligence activity on prevention focuses on (2) since pulling off such actions generally requires the capable planners to coordinate with less capable "feet on the ground" who can give things away. However capable people acting alone which happens occasionally is pretty much impossible to stop (Timothy McVeigh, Ted Kazynski, Kaloyev)

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#156

Post by [deleted] »

jessriedel wrote: post #131
missosoup wrote: post #85

Earlier quoted context omitted.

Demonstrating ASAT against a GEO target would cause a major political incident. The LEO ASAT tests carried out to date caused enough outcry as is. Hitting a GEO target is not difficult. Ignoring dedicated ASAT missiles, any modern IRBM or LRBM can be tasked to intercept a GEO target. Global navigation constellations are certainly going to be one of the first targets in any major hot conflict between world powers. Rea…

> Hitting a GEO target is not difficult. Ignoring dedicated ASAT missiles, any modern IRBM or LRBM can be tasked to intercept a GEO target. Do you have a cite for this?

[deleted]

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#157

Post by beerandt »

lozaning wrote: post #90
sgc wrote: post #73

Earlier quoted context omitted.

It will probably be easier to spot them, since very few planes will show up on radar and not on the GPS system. It might be enough to go take a visual immediately once this is fully online.

I thought the way that they historically avoided detection was to quite literally fly below the radar. Wouldn't that still work with this new system, they just wont show up anywhere?

There are lots of other ways it's being monitored. But as for the flying below the radar, there are these along the southern border and Gulf of Mexico:

https://en.m.wikipedia.org/wiki/Tethered_Aerostat_Radar_Syst...

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#158

Post by Waterluvian »

Patrick_Devine wrote: post #109
FabHK wrote: post #76

Earlier quoted context omitted.

> buying an aviation radio off the shelf and just chatting on the frequency or issuing fake clearances if you want to be a mass murderer Incidentally, I am happily surprised that that never seems to happen. One could so easily create so much chaos at an airport... There is no authentication whatsoever.

The problem with _requiring_ authentication is that it can create a safety issue when communications break down. As a pilot it's not a bad idea to carry a spare handheld radio, or even use a cel phone, when you lose communications. I was flying once with a buddy of mine who was Pilot-In-Command and we lost (or thought we had lost) our radio on an IFR flight back into the Bay Area. What had happened was the Push-to-Ta…

With all the instrumentation in a cockpit I'm surprised there isn't a simple light indicator that your radio is currently broadcasting.

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#159

Post by boarnoah »

cbanek wrote: post #154
wrycoder wrote: post #149

Earlier quoted context omitted.

If you shut it all down and something catastrophic somehow goes wrong with GPS, it will be very difficult to get the thousands of planes in the air back onto runways.

Are they also getting rid of VOR for navigation? https://en.wikipedia.org/wiki/VHF_omnidirectional_range (Sorry, paywall is blocking me)

Not too familiar with aviation or IFR. Isn't VOR primarily a beacon that you use to orient yourself, doesn't seem like it helps the ATC maintain separation etc..

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#160

Post by iudqnolq »

Patrick_Devine wrote: post #109
FabHK wrote: post #76

Earlier quoted context omitted.

> buying an aviation radio off the shelf and just chatting on the frequency or issuing fake clearances if you want to be a mass murderer Incidentally, I am happily surprised that that never seems to happen. One could so easily create so much chaos at an airport... There is no authentication whatsoever.

The problem with _requiring_ authentication is that it can create a safety issue when communications break down. As a pilot it's not a bad idea to carry a spare handheld radio, or even use a cel phone, when you lose communications. I was flying once with a buddy of mine who was Pilot-In-Command and we lost (or thought we had lost) our radio on an IFR flight back into the Bay Area. What had happened was the Push-to-Ta…

Dumb question: how would a cellphone work given they don't work on passenger aircraft?
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