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>> IMMUNE TO JAMMERS No. That is not a thing. At most, one can make equipment less susceptible to jamming. Jamming is not like hacking, it isn't a matter of

>> IMMUNE TO JAMMERS No. That is not a thing. At most, one can make equipment less susceptible to jamming. Jamming is not like hacking, it isn't a matter of whether an attack works or does not. It cannot be fixed via a patch. Pump out enough energy close enough to the target and even a hyper-directional antenna can be jammed. Have a look at military GPS jammers. They aren't the little dongles that you can buy online and run off USB battery packs.

baq 3y ago
But how do these jammers work? They can't point at the sky to blind the satellite because there's no receiver; they broadcast from above ground, so in theory putting your receiver in a metal box with the top removed solves the problem?
- dwighttk 3y ago
  Wait, starlink is one way? How does it know what to send?
  - sandworm101 3y ago
    This is about the GPS antenna on the starlink terminal. GPS is one-way. The terminal needs that GPS signal to predict where the starlink satellites are going to be at a given time. The real "hack" answer is to bypass the GPS system and just feed the starlink terminal its true/known ground position/timing.
  - kbknapp 3y ago
    GPS satellites don't "send" your coordinates to your receiver. Your receiver is just listening to the broadcast signal from several (usually 4+) satellites and based on the strength of that signal determining how far it is from each of those satellites. Which means the receiver is able to triangulate it's own position.
    - meindnoch 3y ago
      >and based on the strength of that signal Wrong. Utterly wrong.
      - nixgeek 3y ago
        Would you explain why?
        meindnoch 3y ago
        No. The Internet is at your fingertips.
        dylan604 3y ago
        That's such a better response than LMGTFY
        serf 3y ago
        an explanation not only helps the ignorant, it reinforces the idea within your own thoughts and perhaps seeds new ideas that are derivative; it even teaches the otherwise uncaring that may happen upon the comment. what you did wasn't that -- but I would just like to point out that simple concise explanations helps the community as a whole; it's not just the ignorant that lose out. Yes, I know it's likely not your job to educate, and maybe it's a bother that someone acts expert on something that they're clearly not -- but those that care to educate serve everyone in the context of an online forum, not just the naive or ignorant.
        vel0city 3y ago
        Here's a great explainer of GPS starting from really basic concepts. https://ciechanow.ski/gps/ https://ciechanow.ski/gps/
        euler_angles 3y ago
        By the time the signal reaches your GPS receiver, it is below the thermal noise floor of even amazing receivers. But each GPS satellite has a unique pseudo-random code (called a PRN) that is within the signal. Receivers that listen long enough can pick out the PRN and thus the GPS signal. I'm no GPS expert, I've read some of the theory had enough of a working understanding to deal with tactical navigation systems, but that was in my past. I remember using El-Rabbany's "Introduction to GPS" text.
  - dylan604 3y ago
    you use your 14.4 dial-up modem for sends. Oh, sorry, thinking about HughesNet.
- bombcar 3y ago
  In theory - but the satellites move, so your box needs to move, signals bounce (both off the ground and the air) and you can put the jammer in the air, too. Also, the more directional you get, the more it may be possible to determine where you are.
- sandworm101 3y ago
  >> putting your receiver in a metal box with the top removed solves the problem No. Radio can turn around corners. It can also bounce off things. Radio is light, but at a much longer wavelength. It is less like blocking a laser and more akin to blocking out sound waves. Blocking line-of-sight to the transmitter would block the laser but would do little to block sound waves.
  - kurthr 3y ago
    Yeah high frequency sound is a good analogy. Starlink is in the 11&40GHz region with wavelengths measured in cm which is about the equivalent to 20kHz. The other really annoying thing about radio waves is that even relatively long wavelengths can leak through really narrow cracks (<1mm) if they are long enough (eg a wavelength) in the right polarization.
  - ethbr1 3y ago
    GPS is on 1575.42 and 1227.60 Mhz, though. Isn't that above the critical frequency you'd get ionosphere reflection at? (Which makes sense, since the signals are coming from outside it at LEO)
- godelski 3y ago
  > But how do these jammers work? Pretend you're having a conversation. Now pretend you're having a conversation at a concert/club/any loud place. So like this[0] > so in theory putting your receiver in a metal box with the top removed solves the problem? You'd think so, but not actually. Think about it this way: you're trying to toss a ball into a cup (or box). Is it easier or harder if that cup has a wide mouth or a narrow one? Make it V shaped for easier visualization and we'd be talking about the angle of that cone. Obviously the wider one right? The extreme other end of this is like a carnival ball tossing game where the cup is just as big (or they cheat and its smaller) than the ball you're trying to throw in. Now pretend you're trying to make that shot from a moving car. You come from far away and drive right past it and you get more points in this game the more shots you score. That's analogous to what then satellite is doing. Remember it comes from over the horizon and then passes to the other horizon. You want to maximize your viewing angle because that gives the satellites more chances to make contact. This is more complicated because you need to kinda do this in parallel as you're handing off data collection to the next satellite coming through so the better viewing angle the more chances you have to smoothly negotiate that pass over. Then there's the whole issue that we're talking about waves instead of particles but I'll let someone else handle that. You can actually find some cool visualizations on the internet about these. See knife edge diffraction. [0] https://youtu.be/m-YSPHib-kg?t=89 https://youtu.be/m-YSPHib-kg?t=89
EA-3167 3y ago
Right, look at the US' current jammer suite, the AN/ALQ-99, while it has issues it's unbelievably powerful. One of the downsides is that it jams the AESA radars of friendlies in the area, including the plane using the jammer itself. The next gen replacement sounds like an absolute monster too, but without some of the donwsides like the need for a ram air turbine to power it.
- dylan604 3y ago
  > One of the downsides is that it jams the AESA radars of friendlies in the area, including the plane using the jammer itself. So you just lob in a heat seeker at the middle of the noise, and hope. Then again, if you have an airborne source of jamming, you know you have bigger problems following. How much effort do you spend trying to knock out the jamming vs preparing for what is inevitably following? Flying in jammers from the opposite direction of an attack to draw in fighters to the wrong area is as elementary as attack options go.
  - kayodelycaon 3y ago
    It's even easier than that. You use a missile (or bomb) programmed to lock onto the source of the jamming.
    - exar0815 3y ago
      Except the jammer oversaturates your receiver or even burns it out. Or causes it to see ghost targets.
    - dylan604 3y ago
      The heat seeker would have problems unless you launched from behind it, which would be problematic if you're launching from the ground, depending on the jamming plane. A steathly plane with the heat sources minimized might not be detected by a heat seeker if launched towards an oncoming source
      - ambichook 3y ago
looofooo0 3y ago
Atomic clock and hard coded GPS Location for the win?!
- martinky24 3y ago
  You joke, but have fun ensuring your clock is synced to everyone elses, even if it is incredibly accurate...
- sandworm101 3y ago
  Good luck syncing a clock at a random location on the ground with one in orbit. In a warzone. Without a connection to the sat with which you are trying to sync.
- raxxorraxor 3y ago
  What do you mean, with a directed signal? I guess it still is a problem of signal to noise ratio even then, if the jammer is powerful enough.
deleted 3y ago
[deleted]

baq 3y ago

But how do these jammers work? They can't point at the sky to blind the satellite because there's no receiver; they broadcast from above ground, so in theory putting your receiver in a metal box with the top removed solves the problem?

dwighttk 3y ago
Wait, starlink is one way? How does it know what to send?
- sandworm101 3y ago
  This is about the GPS antenna on the starlink terminal. GPS is one-way. The terminal needs that GPS signal to predict where the starlink satellites are going to be at a given time. The real "hack" answer is to bypass the GPS system and just feed the starlink terminal its true/known ground position/timing.
- kbknapp 3y ago
  GPS satellites don't "send" your coordinates to your receiver. Your receiver is just listening to the broadcast signal from several (usually 4+) satellites and based on the strength of that signal determining how far it is from each of those satellites. Which means the receiver is able to triangulate it's own position.
  - meindnoch 3y ago
    >and based on the strength of that signal Wrong. Utterly wrong.
    - nixgeek 3y ago
      Would you explain why?
      - meindnoch 3y ago
        No. The Internet is at your fingertips.
        dylan604 3y ago
        That's such a better response than LMGTFY
        serf 3y ago
        an explanation not only helps the ignorant, it reinforces the idea within your own thoughts and perhaps seeds new ideas that are derivative; it even teaches the otherwise uncaring that may happen upon the comment. what you did wasn't that -- but I would just like to point out that simple concise explanations helps the community as a whole; it's not just the ignorant that lose out. Yes, I know it's likely not your job to educate, and maybe it's a bother that someone acts expert on something that they're clearly not -- but those that care to educate serve everyone in the context of an online forum, not just the naive or ignorant.
      - vel0city 3y ago
        Here's a great explainer of GPS starting from really basic concepts. https://ciechanow.ski/gps/ https://ciechanow.ski/gps/
      - euler_angles 3y ago
        By the time the signal reaches your GPS receiver, it is below the thermal noise floor of even amazing receivers. But each GPS satellite has a unique pseudo-random code (called a PRN) that is within the signal. Receivers that listen long enough can pick out the PRN and thus the GPS signal. I'm no GPS expert, I've read some of the theory had enough of a working understanding to deal with tactical navigation systems, but that was in my past. I remember using El-Rabbany's "Introduction to GPS" text.
- dylan604 3y ago
  you use your 14.4 dial-up modem for sends. Oh, sorry, thinking about HughesNet.
bombcar 3y ago
In theory - but the satellites move, so your box needs to move, signals bounce (both off the ground and the air) and you can put the jammer in the air, too. Also, the more directional you get, the more it may be possible to determine where you are.
sandworm101 3y ago
>> putting your receiver in a metal box with the top removed solves the problem No. Radio can turn around corners. It can also bounce off things. Radio is light, but at a much longer wavelength. It is less like blocking a laser and more akin to blocking out sound waves. Blocking line-of-sight to the transmitter would block the laser but would do little to block sound waves.
- kurthr 3y ago
  Yeah high frequency sound is a good analogy. Starlink is in the 11&40GHz region with wavelengths measured in cm which is about the equivalent to 20kHz. The other really annoying thing about radio waves is that even relatively long wavelengths can leak through really narrow cracks (<1mm) if they are long enough (eg a wavelength) in the right polarization.
- ethbr1 3y ago
  GPS is on 1575.42 and 1227.60 Mhz, though. Isn't that above the critical frequency you'd get ionosphere reflection at? (Which makes sense, since the signals are coming from outside it at LEO)
godelski 3y ago
> But how do these jammers work? Pretend you're having a conversation. Now pretend you're having a conversation at a concert/club/any loud place. So like this[0] > so in theory putting your receiver in a metal box with the top removed solves the problem? You'd think so, but not actually. Think about it this way: you're trying to toss a ball into a cup (or box). Is it easier or harder if that cup has a wide mouth or a narrow one? Make it V shaped for easier visualization and we'd be talking about the angle of that cone. Obviously the wider one right? The extreme other end of this is like a carnival ball tossing game where the cup is just as big (or they cheat and its smaller) than the ball you're trying to throw in. Now pretend you're trying to make that shot from a moving car. You come from far away and drive right past it and you get more points in this game the more shots you score. That's analogous to what then satellite is doing. Remember it comes from over the horizon and then passes to the other horizon. You want to maximize your viewing angle because that gives the satellites more chances to make contact. This is more complicated because you need to kinda do this in parallel as you're handing off data collection to the next satellite coming through so the better viewing angle the more chances you have to smoothly negotiate that pass over. Then there's the whole issue that we're talking about waves instead of particles but I'll let someone else handle that. You can actually find some cool visualizations on the internet about these. See knife edge diffraction. [0] https://youtu.be/m-YSPHib-kg?t=89 https://youtu.be/m-YSPHib-kg?t=89

EA-3167 3y ago

Right, look at the US' current jammer suite, the AN/ALQ-99, while it has issues it's unbelievably powerful. One of the downsides is that it jams the AESA radars of friendlies in the area, including the plane using the jammer itself. The next gen replacement sounds like an absolute monster too, but without some of the donwsides like the need for a ram air turbine to power it.

dylan604 3y ago
> One of the downsides is that it jams the AESA radars of friendlies in the area, including the plane using the jammer itself. So you just lob in a heat seeker at the middle of the noise, and hope. Then again, if you have an airborne source of jamming, you know you have bigger problems following. How much effort do you spend trying to knock out the jamming vs preparing for what is inevitably following? Flying in jammers from the opposite direction of an attack to draw in fighters to the wrong area is as elementary as attack options go.
- kayodelycaon 3y ago
  It's even easier than that. You use a missile (or bomb) programmed to lock onto the source of the jamming.
  - exar0815 3y ago
    Except the jammer oversaturates your receiver or even burns it out. Or causes it to see ghost targets.
  - dylan604 3y ago
    The heat seeker would have problems unless you launched from behind it, which would be problematic if you're launching from the ground, depending on the jamming plane. A steathly plane with the heat sources minimized might not be detected by a heat seeker if launched towards an oncoming source
    - ambichook 3y ago

looofooo0 3y ago

Atomic clock and hard coded GPS Location for the win?!

martinky24 3y ago
You joke, but have fun ensuring your clock is synced to everyone elses, even if it is incredibly accurate...
sandworm101 3y ago
Good luck syncing a clock at a random location on the ground with one in orbit. In a warzone. Without a connection to the sat with which you are trying to sync.
raxxorraxor 3y ago
What do you mean, with a directed signal? I guess it still is a problem of signal to noise ratio even then, if the jammer is powerful enough.

deleted 3y ago

[deleted]