GPS Jamming: Major Threat To Drones

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As drones multiply, as they are expected to do, incidents of GPS (or GNSS) jamming and spoofing are expected to rise in concert during the next decade. That poses not just a threat of loss of the vehicles, but also to nearby aircraft and unaware people on the ground, according to Jeremy Bennington of Spirent, a company that specializes in jamming and spoofing defense. Bennington spoke at the AUVSI XPONENTIAL Expo in Denver this week and sketched a threat that’s not yet emergent, but will escalate enough to require drone manufacturers to harden their aircraft against interference.

Bennington said more than 150,000 incidents of jamming or spoofing have been recorded, affecting aircraft, ships and ground vehicles. And it’s not a hard thing to do. “If you want jam GPS, get your credit card out. It’s really rather easily done,” he told a group of XPONENTIAL attendees. The event is organized by the Association of Unmanned Vehicle Systems International and although dominated by aircraft systems, land and marine vehicles are also represented. And all of them have been jammed or spoofed.

In one incident in Hanover, Germany, Bennington said, a GPS emulator being used for maintenance disrupted inbound aircraft navigation and actually electronically moved the runway threshold. It took authorities hours to find the source. NASA’s ASRS has recorded more than 100 incidents of interference, some serious enough to cause aircraft to lose position data. While jamming splatters the signal, spoofing actually fools the GNSS receiver into believing it’s somewhere else. In one well-known incident in the Mediterranean Sea, more than 20 ships were spoofed into believing their positions were miles away from their true location.

Drones are beginning to use a method called sensor fusion—cross checking position with radar, lidar or inertial systems—to defeat spoofing, but these systems add cost and weight. Bennington says the industry will have to respond sooner than later. “We will see the impact as more drones enter service,” he said.

Comments (10)

Would not be dealing with this mess if the Loran-C system had not been de-commissioned. It would have made a good backup for GPS issues.

Posted by: matthew wagner | April 30, 2018 7:10 PM    Report this comment


Halleluja! Finally, somebody who agrees with my plaintive wail about the stupid retirement of Loran.

With regard to GPS jamming/ spoofing, I've been warning about this for at least 20 years. And GPS is THE underlying technology behind ADS-B (an acronym that perverts the definition of "surveilance" beyond insanity). Old YARS-ism: "The best implementation of a conceptually-flawed idea is itself fatally flawed."

The good news? Modern ADAHRS silicon is a great basis for Inertial Nav for Everyman.

Posted by: YARS (Tom Yarsley) | May 1, 2018 5:35 AM    Report this comment

Amen on the Loran C. My background is commercial fishing. In the days before plotters were commonplace we worked in tenths of microseconds, which I figured amounted to about 50 feet, unless we were way out on the end of a chain we shouldn't have been using. I will concede that Loran C did not have GPS's reliability in weather, particularly in snowstorms, but it would be a tremendous backup in this age.
Better not let them get rid of the VORs!

Posted by: Jerry Fraser | May 1, 2018 8:18 AM    Report this comment

I've always been a proponent of keeping loran-c too. Even more so with the "VOR MON" implementation of shutting down VORs. Just this weekend, my student and I were practicing a GPS approach in actual conditions and the GPS lost position literally just as we entered IMC outside the FAF. Fortunately the low clouds only existed along the shore so it was an easy escape back to VMC, but it highlighted the importance of having some other navigation system available.

Posted by: Gary Baluha | May 1, 2018 8:25 AM    Report this comment

When you consider that four installations were sufficient to provide coverage throughout the contiguous United States, using Loran-C as the primary backup for GPS makes a lot more sense than does maintaining 100 or so 1950s-era VOR-TACs.

Every time I'd bend an official's ear, I'd be told: "the decision was made at the very top; it's not going to change; get over it." Every day I thank God almighty that our benevolent government exists to help dumb-asses like me.

Posted by: YARS (Tom Yarsley) | May 1, 2018 11:03 AM    Report this comment

Used Loran C Flying throughout the lower 48 and Alaska in the mid 80's.. Worked well, but had to constantly recheck waypoints because they would move.. Forget the reason for it, but it had something to do with earths rotation and slow updates. Can't say I still dream about those days, but it got the job done.. GPS came along and was much faster processing, updating, and accuracy was much improved.. But, I do believe a swap out is quick and easy..

Posted by: Tom O'Toole | May 1, 2018 11:49 AM    Report this comment

Can't say I share your affection for Loran C, but putting all our navigational eggs into the GPS basket is short-sighted at best. ADS-B aside, the WAAS GPS system is amazing for its accuracy and widespread availability. But, it is neither operated by nor controlled by the FAA, so we are just a big solar flare or military emergency away from losing the signal with little or no warning. If hackers decide that it is a viable terrorist target, there needs to be a stable backup system in place, or thousands of lives could be at stake. If the FAA is hell bent on shutting down VOR stations, then Loran could be a relatively inexpensive backup. In either case, manufacturers need to harden the system (the receiving units) to make it less vulnerable. The FAA needs to pull its head out of the sand and recognize the weaknesses in their baby.

Posted by: John McNamee | May 1, 2018 1:06 PM    Report this comment

All you LORAN hawkers; The last I heard (around 2016) there were grumblings to bring back LORAN (eLORAN), to the point that there were some dollars appropriated to DHS/Coast Guard et. al. to test a few out. I think they actually turn one of the New Jersey Stations back on for testing.

Anybody got any new info? Maybe AvWeb could make a few calls.

Personally, and I know it has shortcomings; I do love me an ADF. Cheaper to maintain than a VOR and it's a simple system that can provide a simple cross check. In my training days, there was nothing like the feeling of checking the map and saying, "Alright, that ADF should be right over there at my 2 o'clock". When the needle swung around and landed at my 2 o'clock, it sure was a warm fuzzy. Pick another ADF and do an eyeball triangulation, it'd get you in the right hamlet, if not the ballpark.

Posted by: Robert Ore | May 1, 2018 2:01 PM    Report this comment

I agree with all on Loran-C. 16 years ago when I bought an airplane with what was then a state of the art box ... a Northstar ... I really liked it. The Northstar boxes had two processors so you could dial in an intersection or other waypoint based upon two position sources and know when you got there. I liked it so much that I bought several more as backups. And then the CG decided they didn't need it anymore because the "magic" GPS was going to do everything but cook dinner. Now this ...

I joined a group trying to lobby them to keep Loran as a backup but -- as Yars said -- it didn't go anywhere. They shoulda listened. But then I don't know why anyone is worried ... the VOR-MON idea will only require you to fly no more than 100nm at find a runway. But that brings up another thought ... since ADS-B will be required to enter Class A through C airspace and above 10k', how will the mythical 'they' deal with that if GPS goes down? More questions than answers.

I wonder what the military will do when all of its smart items get lost, too. Does anyone know if they took out TACAN in favor of GPS?

Posted by: Larry Stencel | May 1, 2018 9:07 PM    Report this comment

. . . and what keep anybody from jamming or spoofing the LORAN signal?

It seems that an onboard autonomous system that does cross checking wouldn't be a bad idea.

Posted by: Phil Nelson | May 4, 2018 12:18 PM    Report this comment

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