9 ms·

I've seen a lot of suggestions floating around on jamming the signal. But that assumes that there is an active operator and not a drone that has been told to go

by geoah 8y ago

I've seen a lot of suggestions floating around on jamming the signal. But that assumes that there is an active operator and not a drone that has been told to go between a pre set list of coordinates. Most high end should support gps navigation so I assuming that you have enough money and don't need to ever recover a drone after it's out of battery you can probably increase your chances of not getting caught.

kierenj 8y ago
Then you jam GPS
- bencollier49 8y ago
  At an airport.
  - kortilla 8y ago
    Which is fine because it’s not necessary for aviation.
  - cjrp 8y ago
    GPS disruption is NOTAM'd or scheduled with Ofcom[1] from time-to-time, although not usually at the airport itself. Given that Gatwick was shut at the time, it wouldn't have affected the aircraft since they weren't able to go anywhere. [1] https://www.ofcom.org.uk/spectrum/information/gps-jamming-exercises https://www.ofcom.org.uk/spectrum/information/gps-jamming-ex...
  - 7952 8y ago
    I wonder how much of a problem that would actually cause? Surely they could announce the lack of GPS on ATC and the pilots could revert to ground based navaids. Of course it might be difficult to keep the effect localised considering how weak the competing signal from space is.
- andrewnicolalde 8y ago
  What about all of the other legitimate users of GPS?
  - kortilla 8y ago
    They suffer a minor inconvenience as precision is lost. The US military frequently does selective jamming near bases and other ‘special’ areas.
    - tomalpha 8y ago
      The tricky bit here is that this is a civilian airport. Jamming GPS could reasonably be expected to cause significant difficulties for civilian planes and pilots. And thus passengers.
      - grogenaut 8y ago
        The airport was already disrupted because of the drones, disrupted to the point of shut down. thus the article.
        amaccuish 8y ago
        As has been mentioned earlier, there are 5 airports in London.
        JimDabell 8y ago
        There aren't five airports in London. There are quite a few airports with "London" in the name, but they aren't particularly close to London. London Luton Airport, for instance, is ~45km north of London, and London Gatwick is ~50km south of London. There's ~100km distance between Luton and the airport that was affected by the drones.
        simonh 8y ago
        How do you think those planes get to those airports? There are planes flying all over the south east going to if from numerous airports. Then there’s the impact on GPS in cars, trucks, phones, police vehicles, ambulances, all sorts of emergency services. We’d have to be extremely careful about potential impact before considering such a drastic step that has a very small chance of actually being effective.
- ff10 8y ago
  I wonder, does that mean loss of precision or complete failure?
  - mpolsz 8y ago
    As always it depends. There was defcon talk[1] about messing with drones and one part of speekers research involved jamming gps signal. [1] https://youtu.be/5CzURm7OpAA https://youtu.be/5CzURm7OpAA
- snovv_crash 8y ago
  It can still do dead reckoning using optical flow and the barometer.
  - snibsss 8y ago
    That is not what dead reckoning is. You’re idea is simply flying by other instrumentation. Dead reckoning would be the accelerometer only, and estimating an assumed possible position based on known facts about the vehicle’s inertia and direction over time.
    - travisjungroth 8y ago
      Using an accelerometer wouldn’t be dead reckoning either. Dead reckoning in an aircraft is measuring airspeed and heading and correcting for expected wind. Using an accelerometer is intertidal navigation.
      - snibsss 8y ago
        > measuring airspeed > accelerometer What exactly would imagine an accelerometer meters? Something other than speed?
        travisjungroth 8y ago
        Accelerometers measure acceleration. This can be used to calculate the groundspeed of the aircraft. Groundspeed is different than airspeed. For example, if a drone was hovering in a 5mph wind, its groundspeed is 0 and its airspeed is 5mph. I was a flight instructor for a few years, and have taught many students how to do dead reckoning. That doesn’t mean I’m right, but hopefully gives me enough credibility that you’ll consider my argument. Each of the Wikipedia articles for these topics is robust if you’d like more detail.
    - snovv_crash 8y ago
      Anything without a global reference is dead reckoning. Optical flow sensors just give you a rotational velocity relative to ground. They don't globally locate you. If you combine it with an altitude sensor it gives the same as an odometer would in a car, or the number of steps you take while hiking.
- sly010 8y ago
  Then the drones fly visually. ANY drone activity will shut down the airport. I think the crucial point to make here is the attacker is inherently in a better position then the defender. There is a buffer zone around the airport anyway. I would aim to mercilessly shoot down detected drones in that buffer zone.
  - lucb1e 8y ago
    Visually? I have yet to hear of a drone that can fly by camera instead of GPS.
    - prawn 8y ago
      I assume most can fly without GPS. I can launch either of my Mavics without GPS and fly free, or it can try to use visuals to maintain location. I've flown within a cave without GPS. The drone drifts and can't really hold position reliably, but it works: https://www.instagram.com/p/BoayncJgAOO/ https://www.instagram.com/p/BoayncJgAOO/
      - jsjohnst 8y ago
        Sure, I’ve flown many times without GPS too, but if one is jamming 1575.42 MHz, it’s a simple matter to do the same for 2.4ghz and 5ghz that’s used for the drone to remote link.
      - NickNameNick 8y ago
        Which is great, but the parent post was describing autonomous navigation and disposable drones as a way for a drone operator to evade capture.
      - lucb1e 8y ago
        But we were talking about not controlling it so they can't jam your controller signal. Sure you can fly manually...
    - A2017U1 8y ago
      I saw MIT opensourcing it 5 years ago. Flying through dense forests too. https://github.com/andybarry/flight https://github.com/andybarry/flight
- janoc 8y ago
  Jamming GPS at an around an airport is not that great idea given that the airliners rely on it for navigation. Granted, they have other means of navigating when the GPS isn't available but in the extremely busy airspace around London this would be just asking for a big problem.
  - lozenge 8y ago
    How big is the area of a GPS jammer? Gatwick is 10km further out than London's biggest ring road and 45km from the centre.
    - jsjohnst 8y ago
      > How big is the area of a GPS jammer? However big you want to make it. All a “GPS jammer” is is a radio transmitting on 1575.42 MHz. Modeling the signal propagation of a transmitting device (Aka radio / antenna combo in this case) is a very very well known field.
      - deleted 8y ago
        [deleted]
  - lucb1e 8y ago
    But the airport was closed anyway. And there's some work by yours truly into targeted GPS spoofing, allowing not only to jam but also to take control of the device using GPS.
    - cm2187 8y ago
      There are like 5 airports in London. You want to be pretty confident your jamming will be very local.
      - opless 8y ago
        There's actually only two "international" civilian airports in London. London City, and London Heathrow. Luton, Stansted, and Gatwick are "London" in name only. All about 30mins drive from the M25.
- vowelless 8y ago
  It is very possible for a drone to fly in a GPS denied scenario.
- cronix 8y ago
  All of them? My drone uses a uBlox M8N which uses 4 different GPS systems (US GPS/Galileo/Beidou/Glonass). It's nice because you can get a GPS lock in just a few seconds, and it's a lot more accurate if you're connected to 20 sats at the same time than just 5 or 6. You can pick them up for about $20 on Amazon. You can also use satellite imagery and machine learning/computer vision with no GPS at all. You just draw a boundary on the sat map that you want it to stay within and it uses its cameras to match. MIT developed some cool drones that can actually fly through a forest at 30MPH without hitting any trees. This stuff is becoming very easy to do. https://www.csail.mit.edu/news/self-flying-drone-dips-darts-and-dives-through-trees-30-mph https://www.csail.mit.edu/news/self-flying-drone-dips-darts-...
- JulianMorrison 8y ago
  If you jam GPS these days, you also get confused ubers, delivery riders and tourists milling around.
mannykannot 8y ago
There is a lot of discussion about how a drone might avoid jamming, which is worth considering with regard to going forward, but the fact is that jamming apparently did bring this incident to an end, so the delay suggests that the relevant authorities were caught woefully unprepared.
- avip 8y ago
  From media - police started with a commercial DJI anti-drone system. That did not work. Then "drone dome" was brought by the UK army. That apparently did work and the drone was grounded. This is in all likelihood the first time ever that system was used in a non-military context, so it's reasonable for the operation to take some time.
sandworm101 8y ago
First priority in not getting caught is recovering the drone. Physical evidence is the bane of all crime. At least have it crash into a deep or fast-flowing river.
panarky 8y ago
In the Gatwick case it appears the drone was remotely operated rather than autonomously visiting a series of GPS way points. I figured the authorities could pretty quickly triangulate the signal to locate the operator. But Gatwick is a bucket of suck so maybe they're just unprepared? Also, I understood that drones are geofenced out of restricted airspace such that they disobey commands to fly where they're not allowed. Geofencing drones: https://www.heliguy.com/blog/2017/02/16/heliguys-guide-to-geofencing/ https://www.heliguy.com/blog/2017/02/16/heliguys-guide-to-ge...
- dreamcompiler 8y ago
  DJI drones are very geofenced. To the point where if you try to fly them inside an enclosure near an airport at an officially-sanctioned event like EAA Airventure, you won't be able to. But many others are not. Drones without GPS for example cannot be geofenced.
  - closeparen 8y ago
    It’s not that hard to build a drone as a hobbyist. Controls on commercially available drones are only going to deter the most casual operators.
- SolarNet 8y ago
  That assumes it's running factory standard software.
- acranox 8y ago
  If my memory of this talk is correct, he demonstrated how easy it was to un-geofence a drone. https://www.youtube.com/watch?v=5CzURm7OpAA https://www.youtube.com/watch?v=5CzURm7OpAA
- dbcurtis 8y ago
  Radio direction finding is reasonably straight-forward in theory, but practice is a challenging art. First, what frequency is the control transmitter on? (or frequency-band/freq-hopping in). If it is one of the usual R/C bands, then that is a limited search space. Or if the perp is not so concerned with observing frequency allocation treaties and regulations, well then now you have a big hunt. Second, what other signals are in that band? Suppose it is in the 2.4GHz ISM band. Given a spectrum analyzer plot of 300 spread-spectrum signals hopping in the ISM band, which 299 are WiFi and Bluetooth and other, and which is the perp? The microwave ovens are easy to distinguish, but still add clutter. So if you can pick on a single signal, then you can use Doppler techniques to get a rough bearing, and directional antennas to zero in. I suspect they had some crews working the problem, but it is a challenge. Anyone interested can look up Amateur Radio “fox hunting” in the US, and in Europe “radio orienteering” is popular. Since signal hunters are not transmitting, no license is required to participate in a hunt.

by geoah 8y ago

kierenj 8y ago

Then you jam GPS

bencollier49 8y ago
At an airport.
- kortilla 8y ago
  Which is fine because it’s not necessary for aviation.
- cjrp 8y ago
  GPS disruption is NOTAM'd or scheduled with Ofcom[1] from time-to-time, although not usually at the airport itself. Given that Gatwick was shut at the time, it wouldn't have affected the aircraft since they weren't able to go anywhere. [1] https://www.ofcom.org.uk/spectrum/information/gps-jamming-exercises https://www.ofcom.org.uk/spectrum/information/gps-jamming-ex...
- 7952 8y ago
  I wonder how much of a problem that would actually cause? Surely they could announce the lack of GPS on ATC and the pilots could revert to ground based navaids. Of course it might be difficult to keep the effect localised considering how weak the competing signal from space is.
andrewnicolalde 8y ago
What about all of the other legitimate users of GPS?
- kortilla 8y ago
  They suffer a minor inconvenience as precision is lost. The US military frequently does selective jamming near bases and other ‘special’ areas.
  - tomalpha 8y ago
    The tricky bit here is that this is a civilian airport. Jamming GPS could reasonably be expected to cause significant difficulties for civilian planes and pilots. And thus passengers.
    - grogenaut 8y ago
      The airport was already disrupted because of the drones, disrupted to the point of shut down. thus the article.
      - amaccuish 8y ago
        As has been mentioned earlier, there are 5 airports in London.
        JimDabell 8y ago
        There aren't five airports in London. There are quite a few airports with "London" in the name, but they aren't particularly close to London. London Luton Airport, for instance, is ~45km north of London, and London Gatwick is ~50km south of London. There's ~100km distance between Luton and the airport that was affected by the drones.
        simonh 8y ago
        How do you think those planes get to those airports? There are planes flying all over the south east going to if from numerous airports. Then there’s the impact on GPS in cars, trucks, phones, police vehicles, ambulances, all sorts of emergency services. We’d have to be extremely careful about potential impact before considering such a drastic step that has a very small chance of actually being effective.
ff10 8y ago
I wonder, does that mean loss of precision or complete failure?
- mpolsz 8y ago
  As always it depends. There was defcon talk[1] about messing with drones and one part of speekers research involved jamming gps signal. [1] https://youtu.be/5CzURm7OpAA https://youtu.be/5CzURm7OpAA
snovv_crash 8y ago
It can still do dead reckoning using optical flow and the barometer.
- snibsss 8y ago
  That is not what dead reckoning is. You’re idea is simply flying by other instrumentation. Dead reckoning would be the accelerometer only, and estimating an assumed possible position based on known facts about the vehicle’s inertia and direction over time.
  - travisjungroth 8y ago
    Using an accelerometer wouldn’t be dead reckoning either. Dead reckoning in an aircraft is measuring airspeed and heading and correcting for expected wind. Using an accelerometer is intertidal navigation.
    - snibsss 8y ago
      > measuring airspeed > accelerometer What exactly would imagine an accelerometer meters? Something other than speed?
      - travisjungroth 8y ago
        Accelerometers measure acceleration. This can be used to calculate the groundspeed of the aircraft. Groundspeed is different than airspeed. For example, if a drone was hovering in a 5mph wind, its groundspeed is 0 and its airspeed is 5mph. I was a flight instructor for a few years, and have taught many students how to do dead reckoning. That doesn’t mean I’m right, but hopefully gives me enough credibility that you’ll consider my argument. Each of the Wikipedia articles for these topics is robust if you’d like more detail.
  - snovv_crash 8y ago
    Anything without a global reference is dead reckoning. Optical flow sensors just give you a rotational velocity relative to ground. They don't globally locate you. If you combine it with an altitude sensor it gives the same as an odometer would in a car, or the number of steps you take while hiking.
sly010 8y ago
Then the drones fly visually. ANY drone activity will shut down the airport. I think the crucial point to make here is the attacker is inherently in a better position then the defender. There is a buffer zone around the airport anyway. I would aim to mercilessly shoot down detected drones in that buffer zone.
- lucb1e 8y ago
  Visually? I have yet to hear of a drone that can fly by camera instead of GPS.
  - prawn 8y ago
    I assume most can fly without GPS. I can launch either of my Mavics without GPS and fly free, or it can try to use visuals to maintain location. I've flown within a cave without GPS. The drone drifts and can't really hold position reliably, but it works: https://www.instagram.com/p/BoayncJgAOO/ https://www.instagram.com/p/BoayncJgAOO/
    - jsjohnst 8y ago
      Sure, I’ve flown many times without GPS too, but if one is jamming 1575.42 MHz, it’s a simple matter to do the same for 2.4ghz and 5ghz that’s used for the drone to remote link.
    - NickNameNick 8y ago
      Which is great, but the parent post was describing autonomous navigation and disposable drones as a way for a drone operator to evade capture.
    - lucb1e 8y ago
      But we were talking about not controlling it so they can't jam your controller signal. Sure you can fly manually...
  - A2017U1 8y ago
    I saw MIT opensourcing it 5 years ago. Flying through dense forests too. https://github.com/andybarry/flight https://github.com/andybarry/flight
janoc 8y ago
Jamming GPS at an around an airport is not that great idea given that the airliners rely on it for navigation. Granted, they have other means of navigating when the GPS isn't available but in the extremely busy airspace around London this would be just asking for a big problem.
- lozenge 8y ago
  How big is the area of a GPS jammer? Gatwick is 10km further out than London's biggest ring road and 45km from the centre.
  - jsjohnst 8y ago
    > How big is the area of a GPS jammer? However big you want to make it. All a “GPS jammer” is is a radio transmitting on 1575.42 MHz. Modeling the signal propagation of a transmitting device (Aka radio / antenna combo in this case) is a very very well known field.
    - deleted 8y ago
      [deleted]
- lucb1e 8y ago
  But the airport was closed anyway. And there's some work by yours truly into targeted GPS spoofing, allowing not only to jam but also to take control of the device using GPS.
  - cm2187 8y ago
    There are like 5 airports in London. You want to be pretty confident your jamming will be very local.
    - opless 8y ago
      There's actually only two "international" civilian airports in London. London City, and London Heathrow. Luton, Stansted, and Gatwick are "London" in name only. All about 30mins drive from the M25.
vowelless 8y ago
It is very possible for a drone to fly in a GPS denied scenario.
cronix 8y ago
All of them? My drone uses a uBlox M8N which uses 4 different GPS systems (US GPS/Galileo/Beidou/Glonass). It's nice because you can get a GPS lock in just a few seconds, and it's a lot more accurate if you're connected to 20 sats at the same time than just 5 or 6. You can pick them up for about $20 on Amazon. You can also use satellite imagery and machine learning/computer vision with no GPS at all. You just draw a boundary on the sat map that you want it to stay within and it uses its cameras to match. MIT developed some cool drones that can actually fly through a forest at 30MPH without hitting any trees. This stuff is becoming very easy to do. https://www.csail.mit.edu/news/self-flying-drone-dips-darts-and-dives-through-trees-30-mph https://www.csail.mit.edu/news/self-flying-drone-dips-darts-...
JulianMorrison 8y ago
If you jam GPS these days, you also get confused ubers, delivery riders and tourists milling around.

mannykannot 8y ago

There is a lot of discussion about how a drone might avoid jamming, which is worth considering with regard to going forward, but the fact is that jamming apparently did bring this incident to an end, so the delay suggests that the relevant authorities were caught woefully unprepared.

avip 8y ago
From media - police started with a commercial DJI anti-drone system. That did not work. Then "drone dome" was brought by the UK army. That apparently did work and the drone was grounded. This is in all likelihood the first time ever that system was used in a non-military context, so it's reasonable for the operation to take some time.

sandworm101 8y ago

First priority in not getting caught is recovering the drone. Physical evidence is the bane of all crime. At least have it crash into a deep or fast-flowing river.

panarky 8y ago

In the Gatwick case it appears the drone was remotely operated rather than autonomously visiting a series of GPS way points. I figured the authorities could pretty quickly triangulate the signal to locate the operator. But Gatwick is a bucket of suck so maybe they're just unprepared? Also, I understood that drones are geofenced out of restricted airspace such that they disobey commands to fly where they're not allowed. Geofencing drones: https://www.heliguy.com/blog/2017/02/16/heliguys-guide-to-geofencing/ https://www.heliguy.com/blog/2017/02/16/heliguys-guide-to-ge...

dreamcompiler 8y ago
DJI drones are very geofenced. To the point where if you try to fly them inside an enclosure near an airport at an officially-sanctioned event like EAA Airventure, you won't be able to. But many others are not. Drones without GPS for example cannot be geofenced.
- closeparen 8y ago
  It’s not that hard to build a drone as a hobbyist. Controls on commercially available drones are only going to deter the most casual operators.
SolarNet 8y ago
That assumes it's running factory standard software.
acranox 8y ago
If my memory of this talk is correct, he demonstrated how easy it was to un-geofence a drone. https://www.youtube.com/watch?v=5CzURm7OpAA https://www.youtube.com/watch?v=5CzURm7OpAA
dbcurtis 8y ago
Radio direction finding is reasonably straight-forward in theory, but practice is a challenging art. First, what frequency is the control transmitter on? (or frequency-band/freq-hopping in). If it is one of the usual R/C bands, then that is a limited search space. Or if the perp is not so concerned with observing frequency allocation treaties and regulations, well then now you have a big hunt. Second, what other signals are in that band? Suppose it is in the 2.4GHz ISM band. Given a spectrum analyzer plot of 300 spread-spectrum signals hopping in the ISM band, which 299 are WiFi and Bluetooth and other, and which is the perp? The microwave ovens are easy to distinguish, but still add clutter. So if you can pick on a single signal, then you can use Doppler techniques to get a rough bearing, and directional antennas to zero in. I suspect they had some crews working the problem, but it is a challenge. Anyone interested can look up Amateur Radio “fox hunting” in the US, and in Europe “radio orienteering” is popular. Since signal hunters are not transmitting, no license is required to participate in a hunt.