3D Robotics


[I'm applying the sysadmin privilage of making an exception to our usual no-military rule here, because the technical issues are sufficiently interesting].

Apply the usual skepticism about the claims, but there's something plausible in the following. As I understand it, the assertion is that Iran basically used radio jamming techniques to force the RQ-170 into RTL mode, then overrode the GPS signal with a fake one that made it think that "home" was an Iranian field. 

An excerpt from the Christian Science Monitor, a good article that discusses what may have caused the capture:

Iran guided the CIA's "lost" stealth drone to an intact landing inside hostile territory by exploiting a navigational weakness long-known to the US military, according to an Iranian engineer now working on the captured drone's systems inside Iran.

Iranian electronic warfare specialists were able to cut off communications links of the American bat-wing RQ-170 Sentinel, says the engineer, who works for one of many Iranian miltiary and civilian teams currently trying to unravel the drone’s stealth and intelligence secrets, and who could not be named for his safety.

Using knowledge gleaned from previous downed American drones and a technique proudly claimed by Iranian commanders in September, the Iranian specialists then reconfigured the drone's GPS coordinates to make it land in Iran at what the drone thought was its actual home base in Afghanistan.


"GPS signals are weak and can be easily outpunched [overridden] by poorly controlled signals from television towers, devices such as laptops and MP3 players, or even mobile satellite services," Andrew Dempster, a professor from the University of New South Wales School of Surveying and Spatial Information Systems, told a March conference on GPS vulnerability in Australia.

"This is not only a significant hazard for military, industrial, and civilian transport and communication systems, but criminals have worked out how they can jam GPS," he says.

The US military has sought for years to fortify or find alternatives to the GPS system of satellites, which are used for both military and civilian purposes. In 2003, a “Vulnerability Assessment Team” at Los Alamos National Laboratory published research explaining how weak GPS signals were easily overwhelmed with a stronger local signal.

“A more pernicious attack involves feeding the GPS receiver fake GPS signals so that it believes it is located somewhere in space and time that it is not,” reads the Los Alamos report. “In a sophisticated spoofing attack, the adversary would send a false signal reporting the moving target’s true position and then gradually walk the target to a false position.”

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  • As I recall the only GPS on board was the pilots own personal hand held.

  • Don't see so many U2's about Akrotiri (Cyprus) as Last year. Or see any of the boys in Yellow. Glowhawk was set to replace them. Have seen a few drones but not Global hawks. Most of the U2 ops.over middle east were guided from a porta cabin in US. plus a very good autopilot. Pilot only there to make a mid flight change of route and land the pig.

  • @Jason -- Minor point, but I believe the grill is there to block radar from getting to and bouncing back from the turbofan.  I first saw them for this purpose on the F-117.  I agree, though, the one on this drone looked pretty hokey to me.



  • I think this is fake information for civilians. 

    Cruise missiles finding the targets since 40 years without GPS signals. You need only a fiber optic gyroscope(because of zero drift) + compass + airspeed sensor + acceleration sensor for finding any location on the earth. Only integral functions enough for finding direction and speed. multiple the speed with time and you have the distance.
    By the way, these drones using parabolic microwave antennas for communication like standard sailboat satellite tv antenna trackers(basically 4 LNB on the focus point or a rotary LNB). If you know the antenna position and satellite position, you can calculate the ship position easily. you dont need any gps like device.

    And how about altimeter? Iranians hacked the air pressure too :)))

  • This looks more like some new Hollywood movie premiere than something serious.

  • Yes, celestial navigation was used on the SR71 back in what, the 60's. GPS is just an easy add on to other proven navigation methods. You can bet the redundancies in an RQ-170 more than cover loss of communication. You can also bet that if communication is lost, it doesn't rely on GPS alone, especially if it suspects a bad GPS signal.

    As for the photo of the supposed aircraft, are you kidding me! Does that look like a precision aircraft to you? It doesn't even look symmetrical enough. It is also too smooth, there should be subtle hatch lines. That looks like a big glassed piece of foam. The grill on the front is killing me. If you want to fake a photo of a billion dollar aircraft, don't add a ceiling light egg crate to the intake. I guess it could be some sort of cadalitic converter / honeycomb style intake to smooth out the air but I still don't buy it.

    Maybe the US did loose a drone but I don't believe for one second that Iran brought it down and I sure don't believe that what is in that picture is it.

    Ehren, I agree with you, did someone hack a super secret spy plane and convince it to land or did someone build a terrible foam fake and say they hacked into a super secret spy plane and convince it to land.

    It seems to me that if you could actually pull this off that you would have that thing opened up for all to see. There would be tons of detailed pics and they would all look very real.
  • It wouldn't be the first time that a military contractor skimps on security.


    Maybe they felt too safe. This is the first time an electronic attack succeeds in this way (if true), so maybe they were thinking they could get away with it for a few more design iterations.

  • Celestial navigation involving daylight capable star tracking obviates the need for GPS.

  • As a GNSS receiver designer (GNSS includes GPS, GLONASS, GALILEO, and all the other future constellations). I can tell you that they 99.999% did not spoof the GPS M-Code signals (spoofing civilian signals is easy that’s why the military doesn’t use it). If they did, they would be bragging about that, not capturing the drone. That would be a much bigger 'win' for them. They likely just jammed the signals since GPS signals are so weak (in the noise floor).

    I do think it's embarrassing that jamming GPS would be cause for the drone to just come down and land. I would also guess that loss of GPS would be a definite requirement/test case for Lockheed Martin's flight test campaign. I guarantee that somewhere Lockheed Martin and the Air Force trying to reproduce the failure as we speak.

    Who knows what happened, things go wrong in manned aircraft too, wasn't there a P3 recon plane that had a mid-air collision and was forced to land in China?

    I'm hoping for a Trojan Horse scenario, maybe we let them think they took it over and a few commandos snuck out at night :-D

  • Wow what a fantastic story from two sides, the Iranins and the CIA. Two groups that you can count on a fabricated story. Which one is lying? They both are.
    The CIA crashed a drone that's all they admit to.
    The Iranins say they captured the drone intact. Yet all they show is what looks like a foam and fiberglass copy from some pictures on google. Show some hardware if you have it surely the landing gear would make a nice display. Heck open a maintance hatch show the inside. They can't their photo is just a artistic model of some pictures off the Internet. They can't even show the bottom. Cause it wasn't finished in time for the photo.
    Alas they don't have the drone or what they have is damaged beyond recognition.
    Occam's Razor cuts both ways. Did someone hack into a super secret spy plane, or did some one build a model Airplane and try to claim they captured the flying infidel?
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