Regarding posts about spoofing and maintaining radar, it was my understanding that the radar sets that most ATCs used was not actually powerful enough to get direct returns from commercial aircraft, and relied on amplifying transponders to be able to see them. Supposedly only militaries operate radars powerful enough to see aircraft directly. Can anyone who knows more confirm or deny? If that's true, I guess we're already in a world were ATC info could be spoofed.
No you wouldn't have to "fake" the primary radar return.
Civilian Air Traffic Controllers in the US, Australia and numerous other countries only have Secondary Radar.
It used to be the running joke when I learnt to fly.
"How is a Cessna 150 like a Stealth Fighter?"
"With the transponder turned off.. neither will show on secondary radar"
The US Air Force, NORAD and NATO still maintain primary Air Defense radar. Especially in the US, a business jet or airliner without a functioning and active transponder is likely to get intercepted by a F-16 and escorted to land at the nearest suitable airport.
ATC radar regularly loses small planes on 'primary' radar (primary radar being pure radar), and has to rely on the transponder. There are many areas where you simply don't have primary coverage, especially close to the ground. I've flown through military controlled airspace where they lose radar contact with me in a Cessna less than 10 miles from the base.
Note: I only have limited experience with ATC Radar (small number of models in the US).
Based on my experience, ATC Radar have no difficulty seeing commercial aircraft with a high probability of detection and low probability of false alarm.
Source: completed a performance assessment of several such systems in the early 2000s against their legacy counterparts using aircraft beacon systems as a source of “truth”.
If I remember to come back to this later, I’ll write a little post showing the theoretical detection performance of such a system. If you’d like to try the exercise yourself, the relevant worksheet is a Blake Chart and you can look up surrogate parameters for the Radar via checking the ASR-XX pages on Wikipedia (e.g. ASR-9 or ASR-11). Finding Radar cross sections (RCS) for commercial aircraft models is similarly straightforward. The system is logarithmic so as long as you’re in the ballpark you’ll be close.
They don't 'deploy' anything. There are no radar reflectors. They just turn on their transponders and anti-collision gear (ACAS). Civilian radar doesn't generally detect reflected energy. It just listens for transponders, which are infinitely more powerful than any reflections. Turn those off and civilian ATC is practically blind whether you are a stealth bomber or 747.
The fighters can actually receive the radar information from AWACs, so the pilots see the radar image. However, just like not having total CAPs coverage over the US, there's not a lot of AWACs coverage either. I'd be shocked if there's any mechanism for them receiving civilian ATC radar. To that end, how much radar coverage is actually there? Isn't civilian traffic pretty much IDs broadcast from the planes?
Most civilian ATC radars are 'Secondary' radars which depend on cooperative transponders on all aircraft. If you turn your transponder off, the system doesn't work.
US ATC uses 'Primary' radars as backup for locating aircraft that don't have transponders or don't have them on. Militaries use Primary radars for most of their activities. Other articles don't provide distinction on what type of radar was used.
Radar can tag any aircraft currently in public flight. Whether that radar can provide accurate and adequate targeting information to weapon systems is not proven at all.
ATC operates on secondary radar (transponder data). If there is no transponder, it would not appear on their scope. Some facilities have an option to switch to primary radar, but it is not usually monitored.
The primary surveillance radars at airports are unlikely to detect an object as small as these, they just don't reflect enough and I suspect even if observed they would be ignored by software because of their small size and low speeds (basically, they do not look or act like airplanes).
The secondary surveillance radar, which is now the main system used by ATC, would be completely blind to them, as it relies on active equipment being installed in the aircraft. Requiring the installation of transponders in drones might be tempting, but they are large and expensive compared to a quadcopter, so it's impractical.
I don't think stealth aircrafts normally have trackers or anything broadcasting a signal. Kind of defeats the purpose...
I did read that stealth aircraft have transponders installed when operating in US airspace, so commercial radar can see them better. But it was not installed on this flight.
The range at which Radars can detect planes is a lot shorter than most people seem to believe. Ground based Radars have an effective range of something in the region of 200miles due to the earth's curvature. To get around that you either have to have air based Radars (such as the E2-Hawkeye used by US carrier groups), or more exotic/experimental types of radars which bounce off the ionosphere.
The limitations of radar are part of the reason why Aircraft have transponders - you can pick up an actively broadcasting radio from far greater range, and you're not relying on getting a clean bounce back from the aircraft. They're also the reason why carriers carry multiple E2s - a radar on the top of a mast on a ship simply can't see far enough.
Spoofing radar signals isn't exactly new, and the ability to do it on the ground (so to speak) shouldn't be surprising. The military has been doing it for decades.
Also, it doesn't take nearly the sophistication of the system demo'ed here -- a chaff canister released into traffic would, I imagine, play twenty kinds of havoc on any autonomous driving system that relied on radar.
> It's secondary radar so it only sees planes with a transponder, but that's usually all of them.
In particular we're talking here about aeroplanes on an approach to a major airport (if they aren't on approach then by definition they aren't choosing between ILS and a visual clearance, and if it isn't a major airport why are we trying to bunch them up more?).
All US major airports have a "Mode C veil" which means there's a regulation requiring aircraft near those airports to have transponders ("Mode C" is a transponder mode in which the aircraft reports its own assessment of its altitude based on air pressure as well as a four octal identifier).
Pilot friend of mine says they do occasionally get alerts from ATC for unidentified primary radar targets near their aircraft while in flight. Usually this turns out to be a flock of birds, bunch of Mylar party baloons and such but in light of all these reports “We’ll be looking a bit more closely for flying tic-tacs now!” ;-)
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