F-35's radar invisibility cloak in question

This isn&#x27;t strictly just about a weakness in the F-35&#x27;s radar resistance, but that the whole concept of &quot;stealth&quot; aircraft may be limited in the future thanks to ever increasing computation power and clever usage of existing radio waves (making effective, passive, &quot;radar&quot; that cannot be easily overcome). But as the article points out, this cannot yet be used for guided missiles, and is very early tech regardless.<p>I suspect the future won&#x27;t be &quot;super weapons&quot; like the F-35, but instead just &quot;mass&quot; weapons like tens of weaponized drones. Where the mission isn&#x27;t to be invisible but to simply overwhelming enemy defenses (essentially the World War I strategy, but without the massive numbers of dead soldiers).<p>PS - The people pointing out that the F-35 had radar reflective disks added didn&#x27;t seem to have understand the article (or technology). This is using entirely different methods to detect the aircraft, not radar waves, so that&#x27;s irrelevant. The F-35 could be broadcasting a transponder, and it wouldn&#x27;t undercut the technology discussed.

I&#x27;m not sure I&#x27;ve ever seen stealth sold as an &quot;invisibility cloak,&quot; except by press lacking subject matter familiarity.<p>The pitch I&#x27;ve seen in settings that <i>do</i> have subject matter familiarity is that stealth decreases the detection range for a given power &#x2F; bandwidth &#x2F; noise tolerance. Could your opponent use more power? Sure, but then they&#x27;re easier to missile lock and destroy. Could they use more installations? Sure, but then they have to maintain them and their communications. Could they crank up the sensitivity? Sure, but then they have to deal with false positives and increased vulnerability to jamming. That goes especially for passive radar. Don&#x27;t get me wrong, it&#x27;s still an arms race, but it&#x27;s not as cut-and-dry as this piece would have you believe.<p>Also, it&#x27;s a VHF technique, which is low enough frequency that I&#x27;d bet active cancellation is practical, possibly even through a software update :)

The weakness in F-35&#x27;s have been well known for a long time now.<p>They&#x27;ve been well known since that a F-117 was shot down in 1999 during the Serbia conflict. The actual event was mostly due to bad operational tactics on the American&#x27;s side and a very lucky shot, but it did highlight that it was possible to detect stealth fighters using coldwar-era Soviet technology.<p>The problem is that the stealth is specifically geared towards XHF frequencies, which are the frequencies used in radar guided missiles.. which are the favored missiles for the USA.<p>However the planes lack the physical size and features necessary to completely absorb VHF radar. VHF lacks the resolution necessary for guided missiles and VHF radar stations must be very large, but it can be used to monitor air traffic over vast areas.<p>So if you detect a aircraft on VHF and then point your XHF radar at it and nothing shows up... Then you know you are dealing with a USA stealth fighter.<p>Stealth has been heavily oversold to the American public, but foreign governments are not so vulnerable to USA industrial-military propaganda.<p>This doesn&#x27;t mean that stealth is worthless. It does dramatically reduce chances of detection, just doesn&#x27;t make them invisible. They are still largely invulnerable to radar-guided missiles. The size of VHF radar arrays needed precludes their use on other aircaft.<p>So to make this sort of thing still requires a sophisticated network connecting large and easily found radar stations, which themselves can be targeted and disrupted in a combat environment. There is still major hurdles needed to solved before it would be possible to actually shoot down these aircraft with radar-guided missiles.<p>Also this technique doesn&#x27;t work as well against aircraft the size of B-2 bomber.

These articles are spectacularly uninformed, jumbling together claims which have never been made, uninfomed guesses and lack of domain expertise. It is more interesting as a propaganda exercise, conceivably so Boeing&#x2F;Dassault&#x2F;Saab can sell their planes more competitively, or so the RADAR operator can get more government funding.<p>Problems with the article: - The F35 isn&#x27;t flown to air shows in &#x27;war mode&#x27;. It has a bunch of reflectors added to increase its RADAR signature. It is only naked when it might be used in anger or over test ranges, and the USAF is very careful to make sure non-JSF program RADARs are off, or have the recordings deleted.<p>- Passive RADAR is a real thing that works, but it only gives a general location. It would be meaningless to try to send a link track to an interceptor or SAM site from a passive RADAR system -- all you could do is call and say &quot;look sharp chaps&quot;.<p>- When you want to shoot at it, your S band (ground) or X band (interceptor) RADAR will have a very hard time picking it up or maintaining lock (because its signature changes depending on aspect, and obviously the pilot will manoeuvre to minimise). Meanwhile your ground receiver is getting jammed and transmitters are getting blown up by JDAMs.<p>- Passive RADAR can also be jammed and deceived. How many times will you scramble interceptors for a false passive detection?

This is a big stretch.<p>A radar manufacturer claims they can detect an F-35 which was equipped to be detectable but the radar maker claims that the devices uses to make the plane visible to radar didn&#x27;t matter because they were tuned to a different frequency.<p>They&#x27;re just selling radars.<p>The thing about stealth is that a tiny aberration can turn an invisible plane into a flying barn. It doesn&#x27;t matter if the devices used to make the plane visible were for different bands, it&#x27;s radio, nothing is exact. They obviously made the plane visible to more than just the target design.<p>On another level, there are various maintenance things that are done to make the plane stealthy when in operation that wouldn&#x27;t be done going to an airshow.<p>And finally, no one says the F35 is totally invisible to radar in all circumstances. It is especially detectable after it has passed your current position. The value of the stealth is that you don&#x27;t detect it until it&#x27;s on top of you or has already fired on you.<p>In a real air-superiority fight, F-22 and whatever other classified drones and planes would be the first wave and clear out a path for the less stealthy but more versatile F-35.

So they managed to pick up a stealth jet.. that was equipped with special markers to make it extra visible (for air safety outside of combat), with additional help from a strong polish broadcaster... with information knowing exactly when and where the aircraft would be?

I would be real curious how this passive radar design helps in an actual war environment.<p>Even if you discount all the possible issues like the F-35s not being in &quot;stealth operational mode&quot;, having reflectors, etc.. this is not a real world test at all.<p>In the real world test there will be a massive amount of ECM energy hitting this passive radar... it might totally blind a sensor like this. In addition a lot of the civilian radio frequencies&#x2F;transmitters will be getting knocked offline and it won&#x27;t have it&#x27;s energy sources.

Interesting, apparently it&#x27;s because of &quot;passive radar&quot; which I&#x27;d never heard about before...<p>&quot;Passive radar equipment computes an aerial picture by reading how civilian communications signals bounce off airborne objects.&quot;<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Passive_radar" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Passive_radar</a>

Midway through the article it finally mentions that this was with the &quot;radar invisibility cloak&quot; turned off by installing Luneburg lenses to make it radar visible. I don&#x27;t doubt that there are current advances in radar technology that weaken the stealth claims of the F-35, but I don&#x27;t think that this specific case demonstrates this.

Goes a long with a story I heard last year concerning the presence of a German radar and electronics company at the ILA. The story goes that Lockheed didn&#x27;t want to fly the F-35 as long as the most advanced radar was on premises. After the radar was moved the F-35 cleared. Also, the radar was set up further away. And the F-35 successfully located. (I wasn&#x27;t there, so that is a second hand story).<p>EDIT: The Spiegel reports more or less the same story, occurred in Aptil 2018. The radar comes from Hensoldt, a former Airbus subsidiary.<p>And, as already stated in another comment, it was passive radar in the sense it took existing signals and analyzed them and their absence.<p>EDIT 2: Yeah, submitted article reports the same story... Lazy me...

It&#x27;s worthwhile to note that while passive radar might be able to detect stealth aircraft, there&#x27;s not much that can be done other than that. Passive cannot guide missiles, and active radar is the only method used to guide missiles. So even if you detect a squadron of stealth aircraft, what can you do about it?

Wait, the passive detector was set up only &quot;a couple kilometers&quot; away from the jet? At that range, I&#x27;m not surprised you can detect it up with passive radar. You could also detect it with an infrared sensor, a pair of binoculars, or even just listening for the jet engine.

In the future, due to advances in radar tech, satellite and others. Skirmishes between highly advanced nations will likely emphasize the use of swarm drones to serve as a battalion and a distraction against the more technically advanced and less defended solutions (e.g. F-35).<p>Whenever someone looks at the F-35 and others, you should aim to build a holistic picture of what &#x27;X&#x27; feature serving sub-optimally could entail, not just &quot;Invisibility cloak has weaknesses under these specific conditions, therefore it is a failure&quot; and whether the group behind optimizing the aircraft is aware of it and accounts for that when upgrading and &#x2F;or sending it on missions.

This is trivial to see. There will be a F-35 demo at Fleet Week in SF this weekend.<p>Turn on your TV to a UHF digital channel during the demo. Watch the interference. Now, it could all be reflectors, but you get a sense how a bistatic RF detector could work.

All comes down to whether the Luneburg lens reflects background noise too. If yes then this is of little use and the result is tainted.<p>If not well that could be a game changer<p>A bit of Google suggests that they are indeed frequency specific see link. So that sounds like it has real potential<p><a href="http:&#x2F;&#x2F;targetsystems.qinetiq.com&#x2F;static&#x2F;media&#x2F;files&#x2F;Luneberg_Lens_2015.pdf" rel="nofollow">http:&#x2F;&#x2F;targetsystems.qinetiq.com&#x2F;static&#x2F;media&#x2F;files&#x2F;Luneberg...</a>

Misleading. The article says things like the F-35 is &quot;designed to be undetectable by radar.&quot;<p>Nothing is designed to be undetectable by &quot;radar.&quot; &quot;Stealth&quot; aircraft are designed to be &quot;invisible&quot; (low-observable, really) in one or more radar <i>bands</i>. Once you get outside those EM bands, the aircraft is obviously detectable (e.g., you can see it because your eye doesn&#x27;t operate in the X band).

For some reason there is the expectation that a new weapon generation is somehow completely infallible and will be able to defeat any future generation. Except new generations of tech make the old generation obsolete. Nothing more nothing less. A non stealth aircraft will have an extremely hard time against a stealth aircraft.

I recall that in at least one case an F-35 used for an airshow demonstration had visible deterioration of the stealth material forward of its canopy. It seems that the low-observable systems used by the F-35 are very maintenance-intensive and that the jets used for shows may not be in combat-ready condition.<p>(or, if you prefer, maybe the jets used for demonstrations are intentionally damaged in visible ways so that there is a convenient excuse for the ease of detecting them on radar)<p>edit: I was thinking of the F-22, see comments below for a source. But similar considerations probably apply to the F-35.

Where there are no existing civilian emitters, such as FM stations, it would seem possible to deploy transmitters deliberately to create a hostile RF environment to assist the passive radars.

I&#x27;ve been looking for a source, but I remember a previous air show incident where a stealth aircraft was detected and the excuse was that the active stealth system was not turned on, i.e. the aircraft would have used electronic active radar cancellation in addition to stealthy body design if it had been in actual combat.<p>Whether any electronic system would help against passive radar, or would in fact make things worse, is another question.

I wonder if these F35s had external fuel tanks attached, for the long flight back home?

Anything made by man can be defeated with enough effort, time, and people.

Tracking any aircraft, stealth or not, isn&#x27;t the issue. The issue is whether you can get a weapons grade track.

If this is true then this is bad.<p>I always warned that the F35 is a one trick pony. Can&#x27;t fly fast, can&#x27;t fly far, can&#x27;t carry much load, can&#x27;t dog fight, needs ton of maintenance and may or may not be invisible.<p>By definition, no plane can be invisible. It is a questions of frequencies and angles you look at it. This plane was not build to bomb Syria or Iran. If the German radar can see it, they Russians and Chinese can detect it for sure.

Lies. I&#x27;ve been reassured by the highest authority in the land that this jet is <i>literally</i> invisible.

I rant about the F-35 a lot, but seriously: this thing is a trillion-and-a-half dollar shitheap, and this is just the latest proof.<p>What&#x27;s really damning about this news is that it calls the entire value proposition of the plane into question. By which I mean, every time someone like me points out that the F-35 loses dogfights to planes from two generations ago, the apologists always come in and say that doesn&#x27;t matter because the stealth and ECM technology means it will never be in dogfights, only BVR engagements.<p>But if you think about, that statement is essentially a gamble. It&#x27;s a wager that our stealth and ECM technology will <i>always</i>, for the entire 40+ year projected lifespan of the plane, be ahead of competitors. Is that a safe bet? I don&#x27;t think it is. This news shows it, and that&#x27;s only what&#x27;s publicly admissible. Imagine what Russia and China have that they&#x27;re not talking about.<p>This thing is a piece of junk based on multiple failed ideas (V&#x2F;STOL, stealth and ECM obsoleting actual combat performance, on-the-fly development, etc.) and it needs to be scrapped yesterday and started from scratch.