As Scottie on Star Trek said, ~"The more complex the plumbing the easier it is to clog."

Sorta stopped watching this channel over the years because i fell out of my passion for space exploration and began my career in planning and defense analystry, lets just say that seeing you start talking about my field in a actually correct and well informed way now makes me happy. Thanks Scott!

I was on the original GPS receiver project at Rockwell Collins, Before you de-spread the signal, it is below the noise, so an early anti jam feature was to have an antenna with a number of electronically steered nulls. If you heard anything coming from the antenna, you diddled the direction of the nulls until it went away. Then you fed the remaining noise into the de-spreader.

My favorite Douglas Adams quote of all time!...."The ships hung in the air much in the same way bricks don't." I still remember reading that as a kid nearly 40 years ago and being so taken aback, "how could anyone think to write so clever?!"

<a href="#" class="seekto" data-time="840">14:00</a> In case any of you haven't read The Hitchhiker's Guide to the Galaxy for a while, here's the quote: *“The ships hung in the sky in much the same way that bricks don't.”* ― Douglas Adams, The Hitchhiker’s Guide to the Galaxy

Hey Scott! Very nice primer on jamming vs. spoofing. As a professional pilot allow me to state for the worry warts out there that the vast majority of aircraft that fly long range oceanic or remote continental routes utilize multiple sensors in their FMS (flight management system) computers for system differential redundancy. For the most part they utilize a combination of GNSS with INS (inertial navigation systems). So if interference is suspected we can manually "separate" the two since overwater the INS uses GPS data to "refresh" the INS position solution, and take out the drift error that accumulates over time. Also we can perform this "single source" navigation ahead of time if we intend to conduct flight ops into or out of known areas of interference.

Scott knows where his towel is.

This is one of the better descriptions of GPS jamming/spoofing that I've ever seen. I particularly appreciate your discussion of the complexities of spoofing, and the need to use highly directional antennae to "target" individual receivers. The interesting thing is that both the Ukrainians and the Russians are known to be doing exactly that to defeat GPS-guided munitions with INS sanity checks (if the munition has INS then it can detect discontinuities in the GPS position, so the spoofing signal has to gradually "walk" it off course)

Controlled Radiation Pattern Antennas (CRPA) can "throw a null" towards the jamming source so the jamming energy doesn't get into the receiver. Such antennas are larger, heavier of course (and more expensive - and as "active" systems need a processor). So military receivers "tell" the CRPA system what direction to throw the null. The antenna with the "rings" around it is called a "choke ring" antenna - originally designed to resist multipath. Many survey antennas were (are still?) using this technique. WAAS ground stations still use them. GPS signal weakness is by design - it's part of the spread spectrum design. The military signal (P(Y)) code has a much wider bandwidth, so it takes more energy to jam across the receiver bandwidth. Further there are 2 frequencies in use (L1 and L2), so jamming needs to cover the two separate bands. Military receivers are also designed to resist, detect and avoid spoofing. Most esp. when used in the encrypted mode (Y code), spoofing is fairly impossible (the crypto code is changed every 7 days). Further (unlike civil C/A code which repeats every 1 ms), military code is much longer than 1 week. (The C/A code has a "Handover Word" to tell the military corelators "where" to jump in on the PR code.) (Before anyone complains "controlled radiation pattern" because that's how you measure an antenna. Its receive gain pattern is the same as its transmit gain pattern).

Russia has been real nice to Finland as a neighbor, for a long time. For example, in recent years they've jammed the GPS near our borders, letting us exercise for it. Thanks!

I kinda expected that Scott would mention RAIM and ground-based alternatives for air navigation readily available and widely used in civil aviation. And maybe more details about why Finnair couldn't proceed on its route to Tartu. Anyway, a bunch of anecdotes: 1. Consumer-grade drones are programmed to refuse to operate in the vicinity of airports based on information from GPS receivers and published airspace coordinates. The folks in the Kremlin in Moscow have been using this feature to prevent these drones from flying close to the Kremlin by cleverly spoofing GPS to make drones think that they are in the vicinity of a major airport (Vnukovo, UUWW). Quite expectedly, the use of "naive" GPS in downtown Moscow has been pain in the a** since they started doing that. 2. GPS has been jammed along the Russian-Ukrainian border since 2014. The thing about this area is that it was one of the most heavily used airspaces in Russia including routes from Russia’s European northern and central areas to Crimea, Sochi, other places in Russia's South, and to popular foreign destinations - Turkey, Cyprus, Israel, Egypt. So when close to the Ukrainian border (usually in the Rostov FIR), RAIM would detect that the GPS info is not reliable, and FMC/FMS would revert to ground-based systems or just INS. Of course, it's moot now as since 2022, there's been a huge no-fly zone in Russia stretching from the Ukrainian border all the way to the Volga. 3. From what you can find in the Estonian AIP, Tartu has an ILS approach, but its STARs are all GNSS-based with no DME/DME back up available. Apparently, Finnair couldn’t do it bypassing the STARs, so they turned back to Helsinki. Ironically, the airport in Tartu is a repurposed Soviet military airfield, so they most probably used to have NDB or even 2NDB approaches, maybe even the arcane Soviet RSBN - until it stopped being a Soviet military airfield. Otherwise, the en-route navigation over Estonia can be performed using DME-DME - the small country has a good DME coverage. So that’s that.

Russia is almost every day doing some sort of GPS jamming here in the northern parts of Norway. Been doing it for many years now :/

There is a quite effective mean to counter spoofing of GNSS-Signals: Take a mulit-system GNSS-receiver, that supports GPS, Glonass, BeiDou and Gallileo. Since it is very difficult to spoof all signals by sending false time information (the base of trilateration) in the exactly same manner, a spoofing attack can be easily discovered and circumvented.

One method to counter GPS jamming and spoofing, at least in the short term (seconds to minutes) is an inertial navigation unit, that keeps track of the position and velocity independent of the GPS data. It can bridge shorter gaps in bad GPS environments. It can also give a warning that spoofing is going on (jamming is obvious from the lack of "service").

One EW technique is to spoof a radar by drawing off a return signal, capturing the radar’s receiver, then dropping the jammer signal. The radar receiver processor then has to re-acquire the target & re-establish a track. Repeating this keeps the radar in acquisition mode, essentially disabling it. A GPS spoofing jammer could do the same thing, as it takes a finite time up to minutes to reacquire real satellite signals & establish location.

I’m a 787 pilot and have seen jamming in several places we fly and we have to turn off our HUD and EGPWS when GPS is off

I remember first seeing a GPS system on a large yacht in 1982. It was about the size of 3 pizza boxes stacked and had a 2 line digital text display. Most of the time it didn't display an updated position, but it would give you a countdown until the next satellite would be in view. When it got a fix it displayed the lat-long, then you had to wait another 10-15 minutes.

Hi Scott. As a airline pilot, one of the best defences, often the only defence we have against position loss is IRS/INS as it is totally internal. GPS is used to update the aircraft position but it’s not reliant on it. If the IRS drift doesn’t match the new GPS signal, we will be warned about the loss of accurate position info. GPS still plays a very important role in our navigation equipment and EGPWS/TAWS still relies on it, as does TCAS to a much lesser extent. Having said that, I’m still an advocate of paper map reading and using traditional navigation methods like celestial nav specifically for the reasons you state. One of my aviation heroes is Gordon Vette for his role in the Cessna 188 rescue in the Pacific and his role in the Mt. Erebus crash a couple years later.

You also get inadvertent jamming in built up areas, with harmonics of thousands of cheap poorly filtered power supplies and LED lights, all creating a much higher noise floor in the area, so that the initial lock of a GPS takes a long time. I often see that, startup time can be up to 10 minutes, or you have the GPS time out, because it cannot get a lock, yet when the power to the area is cut you get a lock within a minute just from the lower noise floor.

Reading that flights in the north have to use manual procedures due to GPS jamming is a common thing when you have russia as one of your neighbours..

You know we all say "hello Scott Manley!" At the screen when your videos start 👋

There is a lot of GPS Spoofing in Israel because of the war. Telling someone you were late because Waze thought you were in Lebanon is a totally acceptable excuse. At one point when flying a Mavic, GPS spoofing started and it suddenly refused to move, and at another time it thought it was in Beirut airport and tried to RTL but had no idea what’s it’s doing.

Thank you Scott, as an agent RF engineer, I learned a lot, mainly that software is now more important than just transmitting radio waves.

I love how your content has grown as a result of you becoming a pilot

There's a lot of GPS spoofing in Moscow. When I worked for a ride hailing app it was common to see drivers "teleport" to a single spot. Hundreds if not thousands of occurances per day, and this is before the thing. It was extreme in the summer and autmn of 2023, we could not use navigation in the center of the city at all. And right now it's working pretty good. RC plane and quad guys say that GPS does not work above 70 meters or so. I guess spoofing is now done in some clever directional way.

I thought for sure you would mention James Bond Tomorrow Never Dies as the quintessential GPS spoofing example:)😂

This is why I’ve loved this channel since the beginning. You’re always learning, and you’re always sharing what you learned. And it is always interesting! Thanks Scott.

My DJI Mini 4 Pro got lost on a way point mission a couple of weeks ago. I'm not sure if it was due to GPS interference, but I couldn't think of any other reason. I aborted the flight and guided the drone back manually so no loss of the vehicle. In Helsinki, Finland.

Thank you for this video Scott. This is something that those of us in the Position, Navigation and Timing space have been saying for years.

Scott; I'm not a pilot, but a mariner. If you read any chart (nautical map), Notice to mariners or text on navigation you will come across this: "Prudent mariners will not rely solely on any single aid to navigation" IMHO, GPS is a single source of navigation information. If the environment changes (e.g. especially strong aurora caused by increased solar activity) such that the satellite signals are unreliable world-wide, we should still have secondary means of navigating.

I flew the 737 to Jordan a few weeks ago. GPS-L and GPS-R failed due to jamming around Israeli airspace. My Garmin Tactix 7 (same as Fenix 7) and inReach Mini 2 continued to operate flawlessly. The inReach has multi-GNSS (GPS, Glonass, Galileo, QZSS, IRNSS and Beidou) with single band (L1). The Tactix has the same multi-GNSS but also multi-band (L1 and L5). Considering the frequencies involved, I suspect the jamming was on GPS L1 frequency only (1575MHz), which may be the only one used by the 737 I operated.

Very good descriptions on the current problems. Thank you Scott for publishing this.

RF interference from USB 3 devices is known to jam GPS signals. I learned it the hard way while trying to debug a Raspberry Pi with a TTL GPS serving as a NTP server. Everything was working fine when using a SD card as storage but no more GPS lock once the content of the SD copied to a SSD attached to a USB to SATA adapter and connected to any of the USB 3 ports of the RPi. I will always remember that eureka moment when I switched the SSD to a USB 2 port and everything started working fine again.

With wide band Internet satellites such as Starlink, would be interesting using them also as backup trackers for Airliners. It would give a more detailed position in real time instead of intermittent pings.

One thing I never throw away is maps...

I was in Madrid visiting the Spanish airforce museum. And when we tried to get an uber back to the city it just showed us as in San Francisco. Both my dad and me. We presumed that the base was jamming GPS but the strange thing is there was a public airport that overflew the base on landing.

Ugh. I work in satellite operations. Every time we go over eastern Ukraine our GPS goes haywire. Usually its just a nusance, but its kicked us into safemode a few times over the last 2 years.

For the past 7 months, my phone always shows me at the intersection of the runways of Beirut International Airport. No matter where I go.

For avoiding spoofing, Galileo deployed OS-NMA which offers authentication. The service is free, publicly available and backwards compatible with existing Galileo capable GNSS receivers. It's a matter of software to make use of it.

An ex employer as with most manufacturers of small cells used GPS for the timing, turns out some specific 4G downlink frequencies clash with the GPS, we'd have to shift to an external remote mounted aerial or if it was our kit switch frequencies.

I work for a farmer and all of the tractors have auto steer. The recent solar flare activity has really been messing with waas/rtk systems. If i could get signal at all, it thought i was going backwards and not where i was. Kind of unrelated to jamming, but shows how potentially fragile the system is i suppose

This is starting to remind me of the electromagnetic back and forth in the Stanislaw Lem book "Fiasco".

"The missile knows where it is at all times. It knows this because it knows where it isn't." As someone who uses GPS constellation simulators to test spacecraft GPS on ground, it's nice to see this video and see how you explain everything! We have a specific license to also repeat GPS signals using transmitters in the building, and great care is indeed taken those signals do not leak out and mess everything up. Fun thing to do is open a maps app on your phone and set it to give you directions somewhere and then play back some spoofed data. Commercial GPS will lock you out above a certain altitude and speed though, so it won't show you in space. But the "where's my device" will have some fun data points!

"Who's doing it" well, considering here in Finland we see news about planes getting jammed when flying near Russian border (typically going to Tallinn), I'd say we can have quite a good hunch on who is doing it.

I would be interested to hear your take on the impact of space weather on GNSS systems. That would be a cool video

Couple corrections: 1) you can spoof gps with a single device (saw this done at defcon in a glovebox where a smartphone thought it was walking around) 2) kind of disappointed you didn't mention iran taking down one of our drones a few years back with spoofing.

Hey, thanks for talking about this subject.

First time I regularly experienced GPS jamming was between 1997 and 2003 whenever I drove my car past Rimini Italy / San Marino on the Italian Motorway. I had my Garmin Pilot III on the dash of my Audi at the time. I think my fastest tracked speed was just past Mach 1.5 at about 1700km/h at sea level tracking me driving in minutes halfway across the Adriatic towards Venice. It's probably the fastest that any car was ever tracked on GPS. And this always happened on an about 40km stretch of motorway passing the Republic of San Marino. But most likely, the signal jamming was linked to Italian military or other security matters. So nothung new, except the jamming range of the Russians, who now cover most os the Baltic sea and the Baltic Countries with only 2 jamming stations at Kaliningrad and St. Petersburg.

"“Say … what’s a mountain goat doing way up here in a cloud bank?”"

I love these topics! Can't get enough

Honestly this is like one of my favorite videos in like awhile I'm really interested in GPS and antenna and ham radio I watched this guy's channel save it for parts that guy does a lot of like DIY stuff and you know amateur and well perhaps I don't know how in-depth his knowledge is but this is like a kind of what i like

Greetings from Poland! Props for Kaliningrad and Poland story ❤

Great presentation. Also, there are many good comments

I work as an ATCO in the Baltics (ESMM) and we encounter it daily. Mostly jamming but some times spoofing. This affects of course the ones doing GPS related SID/STAR but also ENROUTE. We have means to help with navigation aid with vectors and such, but it takes up some capacity.

Great video of interesting stuff! Although, I was kinda hoping you would include info on how geomagnetic storms interfere with GPS, given the magnificent storm we experienced over this past weekend! Maybe next time! ❤ :)

What about using all GNS Systems at the same time? Or are they all being jammed?

Very interesting. You forgot to mention the incident where Iran, allegedly using GPS spoofing convinced an American drone to land on one of its airports. It wasn't a perfect landing but they did capture it and took some photos of it.

Great video scott!

I didn’t know you were in Novato. Beautiful area. Perfect weather. Cool breezes.

The military in my area is jamming GPS in a 50 km radius. Can't fly drones, can't use Google Maps/Waze.

We're jammin', jammin', And I hope you like jammin', too

A timely reminder of how we have become dependent in certain ways on Satellite systems. Thank you Scott.

Thank you for bringing yet another interesting topic! I live in Israel, so imagine my amusement when I started my car navigation system one morning to drive to work, and discovered that apparently I'm at Beirut International Airport :)

I have wrapped my drone in silver foil. 👊

I'm surprised they don't have optical positioning. Using ground imaging to position themselves. With Ir cameras to see through clouds, and on board maps.

A couple of years ago a man was doing his daily construction work at Copenhagen Airport. He dabbled with radio interference equipment and he had some in his van he hadn't turned off. It caused a stirr with the radio control tower and a huge delay in landing and departures until they found the source. He was immediately fired and later on got a sizeable fine.

thanks for explaining this. i've wondered about it for some time.

There is actually a memorial to the Katyn massacre in Jersey City, just across the river from the World Trade Centers

"Spoofing sounds like an act where magicians shoot heroin" - John Oliver

Hi Scott, I'm a 737 captain operating in the eastern Mediterranean and we face this problem every day. Even if we disable GPS updating, it still affects other systems like the "look ahead" terrain display and more importantly the weather radar. It seems that these newer systems have no way of rejecting spoofed signals and it makes flying very challenging.

Galileo has OSNMA, which is essentially digital signatures on the signals (really much more complicated but a neat trick). But it is very new, and none of the current receivers look at that information (that I have been able to get my hands on).

Took the UK years to track down some truck driver that was driving past Westminster every day with a GPS jammer to block his boss's tattler. My ex would take a cell jammer to class, everyone just sort of assumed that room was shielded.

Call me a boomer: Basic map reading skills should be ubiquitous. Great topic/presentation-fly smart!

One quick note about RF jamming in general - you jam the *receiver*, not the transmitter. You don't necessarily have to radiate more power than the transmitter - you just have to have more effective radiated power measured at the receiver.

loved the Douglas Adams reference ❤

There is no Kaliningrad. There is Królewiec now 😊

It would be hilarious If it came out that Ukraine is using GLONAS for their drone's navigation.

this is right up my alley baby

To be fair, there are some places where maps are not even half as reliable as GPS. To use an example from my own backyard: Louisiana. The swamps down here (especially close to the coast) change really rapidly. It is entirely possible for multiple islands to wash away, or for a landform's shape to change, between map publications. If you're unable to see an inhabited area to use as a reliable landmark, and you're relying on a map that was only published last year, and no GPS, I can imagine it being quite hard to do effective navigation.

Clean your room!

Ohh interesting. Now I know why my Waze was shoing I was roaming the sea during latest attack from Iran.

Hey Scott, best most favourite show in a long time. Do you remember a few years ago the US navy had a rash of ships colliding with other ships? They 'explained' it as; poor training, long hours, under crewed etc etc etc. They couldn't tell the world their own Nav system was being spoofed by the Chinese/Russians, could they?

Thanks Scott!

Another great countermeasure is to restart the high power DECCA stations in E-DECCA mode . They work just like GPS satellites but on a low frequency high power signal with no orbital variation as they are solid buildings on the ground . This is obviously limited to own territories but can protect large areas not under heavy bombardment .

Well, I'm gonna have to use this information in a sci-fi story. Thanks, Scott!

<a href="#" class="seekto" data-time="540">9:00</a> aahah PLL sure feels like dark magic at first... And then it feels even darker when you actually learn about it.

Hi Scott thanks for the interesting video ❤

Detecting GPS spoofing for anything but small drones: Just put multiple receivers on your aircraft/ship with as much distance between them as possible. If all of them show the same delay between signals received from different "satellites" then you know that you are being spoofed from a single transmitter. If the spoofer is using multiple transmitters with large distances between them, then it gets more complicated but the GPS almanac should reveal it together with fairly large error in the overdetermined system for some out your receivers.

Thank you, Scott, for keeping us informed of development by the "bad guys".

Your shit's always well articulated to be understood.

The British RAF is in the news today announcing a successful airborne test of an inertial navigation system using quantum interferometry. The measurement frequency is only ~1Hz, and it's not the kind of thing that will fit in an iPhone anytime soon, but the accuracy is unbelievable. The theory is that by fusing data from "classical" optical gyros and quantum sensors, the combined system can have negligible inertial drift over a flight leg, making it possible to navigate precisely without any external references.

I remember when I first started flight simming in the early 00’s, real world pilots were saying GPS would never replace radio nav their argument was what would you do if it failed (that old stand by argument people pull out when a new technology comes out). The same argument could be made against radio nav, or the engine or anything else with the plane.

love seeing this stuff as a PNT engineer

Very informative Scott, thank you. In my travels around Australia, I still see key point, ground positioned navigational beacon points that look well maintained, albeit major distances apart. Is there still a soild network of basic ground navigation beacon points globally that are a back up for long haul/military aircraft sustained in case GNSS systems go off line? Thank you. Mark

Airline type aircraft also feature an Inertial Navigation System. As do some weapons systems. On the aircraft I fly, when GPS drops out the INS kicks in. The GPS, is somewhat more accurate and when it returns, the aircraft can make an abrupt course change to regain the GPS route. The actual jamming systems themselves are also interesting. Russia does not do micro-electronics. These jammers tend to be truck based and very large. They also seem to be mounting smaller jammers to tanks.

A very good video ive worked with RF and high frequency power electronics and some times its like working with voodoo. Good analogue engineers can be like magicians

GPS transmits a low level signal across a very broad spread spectrum. It is normally at a lower level than everything else at any specific frequency, but by doing a convolution across lots of frequencies looking for the signature pattern, you can pull it out of the noise. GPS jammers similarly transmit noise across a broad spectrum.

One thing is to have Inertial navigation system as back up to help the GPS system to decide which is the original signal.

You know there's stuff going down when your tech videos have geopolitics in them, but it's completely warranted.

<a href="#" class="seekto" data-time="84">1:24</a> I know a Captain from the 80's, that could still get lost even if GPS was available then.