Sensor Jamming in Space

[PTNLemay]

I remember back during one of those "stealth in space" discussions I had with my friends that were spurred by long hours browsing Atomic Rockets, I thought up an idea that none of us were able to conclude because we didn't know enough science to figure out if it could work or not. I'm hoping some people here are more knowledgeable.

I remember reading on Atomic Rockets that even humble modern sensors have a phenomenal recovery rate. They can get blasted in the face with high level radiation and be back online the moment the radiation stops. I had my doubts, until I saw this vid by ThunderFoot where he actually puts an iPod (with camera) inside a neutron beam. http://youtu.be/IaQI21LwueM?t=3m01s You can actually see the neutrons striking the camera, blanking out individual pixels for a short while, and the camera recovering near instantly. And this is an iPod... I imagine a military spacecraft of the 22nd century would have something better. So this proves that space jamming would be pretty difficult, to say the least.

But most sensors simply operate using electromagnetic radiation, no? So how hard would it be to take some sort of laser/maser/radiowave cannon, aim it at the enemy ship and shoot at it continuously with sufficiently strong energy to blind them? I acknowledge it would be pretty bad for proper stealth, since you're effectively shining a giant flashlight in their faces (should be easy to track where you are based on that). But while they're blinded you might be able to deploy missiles or dock with an asteroid or do something clever. They'd know where your ship is, but not what it would be doing. Then when the job is done you turn down the beam, they get their sight back, and you high-tail it out of there before they can unleash retaliation on you.

So, how crazy is this idea, and why wouldn't it work?

Edited January 14, 2014 by PTNLemay

[Ignamious]

Well... Without getting into any specifics about something that is illegal to do outside of the military...

Jamming is actually very easy. when it comes to the EM spectrum (thats Light -> UHF -> Microwave) ect. all sensors read a "wave" that bounces back. Thats how the Stealth planes work. I'll talk about the F-117 because it's old stealth technology. Basically it prevents the EM signal from bouncing back to the source thus preventing it from being detected. there is also EM absorbing materials. Those are known as "Passive Stealth"

Now also some old technology is the IR Jammers. they were played with in the '70's+ Basically you get a very bright IR Source and Blast it out "Blinding" the Targeting source. Now... the basics of IR... it's not heat. it's molecular motion (kinda)

Now... a "Cannon" won't work. We'll take your 2.4ghz phone as an example. What is the Actually frequency it uses? We don't know, so what we will do is Blanket the area with with 2.3ghz all the way to 2.5ghz just in case. Well what amplitude is it using? how powerful? can the Target just increase it's gain to get away. can it employ ECCM? (Electronic Counter Counter Measures) with your ECM (Electronic Counter Measures) be able to stealth? Because a VERY simple ECCM method is to just Blow up the ECM. you can VERY easily build a tracking system to target that MASSIVE Radiation coming from you. so as long as your jamming them there missile / turret / Bullet is whizzing right at you following your jamming signal.

There is more to it, but much of it is classified and VERY illegal to do. You make a Jammer at home and your toast (it's very easy to triangulate)

Jamming is more about fineness then brute force. Look at the AN/ALQ-184 and the AN/ALQ-131 Both currently used and operated by the USAF. I can't go into detail about them but wikipidia as some fun info to think about.

http://en.wikipedia.org/wiki/Radar_jamming

http://en.wikipedia.org/wiki/Electronic_countermeasure

The info there is public info and something to think about. In space, there is a lot of background radiation. so ECCM will be FAR superior. as for visual... There is always a way to see, it's called frequency shift. Also known as signal processing if your IR Viewfinder is being jammed use something else. Every object emits some sort of EM radiation. so if the IR range is being blocked try UV or something else. look at the pictures nasa gives on the sun! 4 other views none of which are the visual light scale.

Not saying you can't Jam the target with raspberry but you best know what the target is using before jamming and make sure you can block it all if you want to "blind" them, and thats a LOT of power...

Now that the "Can't be done" is over... how to do it.

Well, by using a very sensitive direction receiver to receive the active signal from the target vessel, you can active a ECM program, and using a separate system as an ECCM you can counteract the Targets ECM and ECCM to try to maintain the Diversion. as for passive devices (cameras, recovers, ect) thats were intelligence comes in. You need to know what they have, and try to block it, you could use a phasing Light pulse Quickly ranging the Spectrum of light in pulses it won't permanently blind them but it will give a very fast strobe effect reducing the ability of the target to get a clear shot (think of moving with a strobe light, thats similar to what it would be like) by using broad spectrum jamming as well as more precise methods at the same time you could denny the target a few sensors at a time. You would need many systems targeting the different components at the same time. A single fighter could not achieve this feat, however a squadron or flight of them could. assuming each bird was responsible for a different subassembly. a larger ship (Similar to a C-130J) could do more but be less manuverable. a few of them could do the same as many smaller. if you had a destroyer sized vessel you could theoretically have most if not all the ECM / ECCM on that ship, providing telemetry and information to the less hardened fighters.

I could go on, but i won't. The ECM field is large and very interesting.

[DaveofDefeat]

So how hard would it be to take some sort of laser/maser/radiowave cannon, aim it at the enemy ship and shoot at it continuously with sufficiently strong energy to blind them?

I'd rather build some sort of laser/maser/radiowave cannon and shoot at it continuously with sufficiently strong energy to KILL THEM.

[Ignamious]

Microwave won't do that, and Radio wave won't do that... LASER is just light (Light Amplification by Stimulated Emission of Radiation) reflective coating would reduce capability and heat absorbing material (an absolute must in space) would also make it ineffective. so something 50% reflective with 75% dissipation would reduce you LASER power to just a fraction.

but that depends on the wavelength of the LASER. if your reflective material is not rated at the LASER's wave it could end up just absorbing all the heat and act as an amplifier instead. but thats were heat dissipation comes in.

Personally... just use a mass driver like a Coil gun or Rain gun to launch a VERY Large and Heavy piece of non-magnetic material (use a sabot to launch the mass). or if we are in the 22 century use Plasma. All the benefits of Mass and Heat. Thermal / Kinetic energy.

[DerekL1963]

But most sensors simply operate using electromagnetic radiation, no? So how hard would it be to take some sort of laser/maser/radiowave cannon, aim it at the enemy ship and shoot at it continuously with sufficiently strong energy to blind them? I acknowledge it would be pretty bad for proper stealth, since you're effectively shining a giant flashlight in their faces (should be easy to track where you are based on that). But while they're blinded you might be able to deploy missiles or dock with an asteroid or do something clever. They'd know where your ship is, but not what it would be doing. Then when the job is done you turn down the beam, they get their sight back, and you high-tail it out of there before they can unleash retaliation on you.

So, how crazy is this idea, and why wouldn't it work?

First you have to know where the sensor you're trying to jam is, so you can aim at it. (And it's trivial to deploy a *LOT* of sensors. Second, they only care where you are, not what you're doing.

Yes, it's crazy. No, it won't work.

[DaveofDefeat]

or if we are in the 22 century use Plasma. All the benefits of Mass and Heat. Thermal / Kinetic energy.

Hate to break it to ya but plasma weapons arnt useful for the same reason trying to shoot air at someone to kill them isn't useful.

[magnemoe]

Hate to break it to ya but plasma weapons arnt useful for the same reason trying to shoot air at someone to kill them isn't useful.

The sharped charge is a plasma weapon and pretty useful, however its has very limited range as in a less than a foot.

regarding high powered jamming, as I understand high powered radars can generate EMP like effects and burn out part of the electronic unless its well shielded.

[Ignamious]

Hate to break it to ya but plasma weapons arnt useful for the same reason trying to shoot air at someone to kill them isn't useful.

Plasma is the fourth state of matter. It's theoretically possible to heat a heavy metal to its plasmatic state and lunch it in a magnetic encasement. Mind you as far as I know metal looses it's magnetic property when it heats up, however the plasma is sufficiently churning it could generate its own magnetic field. This could allow the plasmatic metal to then stay heated for a longer time as it flies towards its target at 10km/s

The sharped charge is a plasma weapon and pretty useful, however its has very limited range as in a less than a foot.

regarding high powered jamming, as I understand high powered radars can generate EMP like effects and burn out part of the electronic unless its well shielded.

True, however most aircraft are EM hardened. And I can tell you now that ALL military craft are as well. It's not hard the harden something agains EMR so that a EMP will not effect it. If you place your electronics in faraday cages you'll be protected and in space you use rad harder anyway. The microchips used in space are already all Rad hardened to prevent the sun from killing them. Hence why solar flairs don't fry every satellite in space even though the charge is so powerful it charges the earth atmosphere! (Northern lights) I actually managed to pick up a few very old microchips that were used for space a few years ago at a summer sale at an electronics surplus store in Silicon Valley, it has a gold top.

[DaveofDefeat]

Plasma is the fourth state of matter. It's theoretically possible to heat a heavy metal to its plasmatic state and lunch it in a magnetic encasement. Mind you as far as I know metal looses it's magnetic property when it heats up, however the plasma is sufficiently churning it could generate its own magnetic field. This could allow the plasmatic metal to then stay heated for a longer time as it flies towards its target at 10km/s

If a plasma charge is held together by a magnetic field then it could be easily deflected by a ship generating its own magnetic field.

[magnemoe]

Plasma is the fourth state of matter. It's theoretically possible to heat a heavy metal to its plasmatic state and lunch it in a magnetic encasement. Mind you as far as I know metal looses it's magnetic property when it heats up, however the plasma is sufficiently churning it could generate its own magnetic field. This could allow the plasmatic metal to then stay heated for a longer time as it flies towards its target at 10km/s

yes however plasma will expand both because its very hot and because it will be positively charged, it would be far more effective to accelrate an slug to 10km/s

True, however most aircraft are EM hardened. And I can tell you now that ALL military craft are as well. It's not hard the harden something agains EMR so that a EMP will not effect it. If you place your electronics in faraday cages you'll be protected and in space you use rad harder anyway. The microchips used in space are already all Rad hardened to prevent the sun from killing them. Hence why solar flairs don't fry every satellite in space even though the charge is so powerful it charges the earth atmosphere! (Northern lights) I actually managed to pick up a few very old microchips that were used for space a few years ago at a summer sale at an electronics surplus store in Silicon Valley, it has a gold top.

Guess its hardened, this is another reason to do it. Anyway an nice way to take out an uav made with off the shelf parts

[Ignamious]

If a plasma charge is held together by a magnetic field then it could be easily deflected by a ship generating its own magnetic field.

Plasma is electrically neutral as a whole, but its strongly influenced by EM fields. you Not much is currently known about heavy metals being turned to plasma. However high density plasma has magnetohydrodynamics suitability. also... you can't easily deflect something with your own magnetic field like that. 10km/s is fast, thats 22,270 MPH. and plasma is not a solid object. it doesn't have only one pole and it's not only positive or negatively charged. think of it more as ferro-fluid.

magnemoe]yes however plasma will expand both because its very hot and because it will be positively charged, it would be far more effective to accelrate an slug to 10km/s

Plasma is mostly neutral because it contains the same amount of electrons (negative) and ions (positive) but it is influenced by EMR, in 200 years who knows what we can come up with. Look at the last 20 years.

Boeing is actually doing Plasma research right now for weapons in it's Phantom Works called DEW (Directed Energy weapons). There are a few different ideas.

Guess its hardened, this is another reason to do it. Anyway an nice way to take out an uav made with off the shelf parts

Yup! if you really want to **** some people off just go to an RC field with a 2.4ghz jammer and turn it on, most of the RC now uses that frequency. bu some still use the 72mhz (easier to jam) so you can do that too. a little math and the know how you can easily make a frequency jammer with radio shack parts, well... mostly radio shack parts.

[PTNLemay]

I leave for a day and a half and the thread starts filling with paragraphs... I'll start by responding to the first couple of posts, work my way through the rest later.

Now also some old technology is the IR Jammers. they were played with in the '70's+ Basically you get a very bright IR Source and Blast it out "Blinding" the Targeting source. Now... the basics of IR... it's not heat. it's molecular motion (kinda)

Yes, that's exactly what I was thinking of. Whatever frequency the sensors are using to watch for the enemy (be it visible, IR or radio) you get a concentrated beam of that and continuously shine it in your opponent's face.

I also like your suggestion about ECCM, that's another thing I suspected would happen. The obvious response to being shone in the face by a hyper strong beam is to shine one right back at them. Maybe confuse them enough that they lose their targetting on you. Though in the hyper-precise world of orbital mechanics I'm not sure how any targetting computer could just "forget" where it's target went. Even if it does get blinded it should be able to extrapolate future positions based on the old observations. The way I look at it, this would really only be useful for situations where the enemy knows where you are, but you're preventing them from knowing exactly what it is you're doing. Like if you've docked with an asteroid base, you shine your beams in their face, unload some kind of cargo, turn off the beams, and run off.

Also don't worry about legal matters, I don't seriously think I'll be doing this. And any scenario that does will be bordering on war anyway, so they probably won't care about lega issues.

There is always a way to see, it's called frequency shift. Also known as signal processing if your IR Viewfinder is being jammed use something else. Every object emits some sort of EM radiation. so if the IR range is being blocked try UV or something else. look at the pictures nasa gives on the sun! 4 other views none of which are the visual light scale.

I imagine this would result in a kind of ECM arms race, with each side trying to design ever more elaborate sensor suites and corresponding jamming systems. Ship A has 5 different bands with 7 different kinds of jammers, but ship B has 8 different bands and 11 jammers. So even if ship A has more guns, ship B might be able to confuse and or distract ship A long enough for B to finish it's mission.

I'd rather build some sort of laser/maser/radiowave cannon and shoot at it continuously with sufficiently strong energy to KILL THEM.

I'm sure I could think of situations in the future where actually destroying an enemy ship would lead to unacceptable escalation of conflicts, like a Cold War in space. But blinding the enemy would be skimming the line without crossing it.

[DaveofDefeat]

I'm sure I could think of situations in the future where actually destroying an enemy ship would lead to unacceptable escalation of conflicts, like a Cold War in space. But blinding the enemy would be skimming the line without crossing it.

O yea, it may not start a war, but if you go up to a Chinese warship and start jamming them, chances are they are going to shoot you.

[Amram]

I'll preface with, all of this is public knowledge, so if I go and say something you never knew, don't go assuming im sharing secrets, cause its all easily found with a little google-fu and a little reasoning.

This is a bit long, so if your not inclined, i don't care, skip this at will, its just info.

I'll focus on radar as it is in the modern world, and the assumption that much of the techniques used will apply to most active electromagnetic sensors in the future for some time. Radar, if used in space will certainly be vulnerable to these very techniques just as it is now. I will also skip passive systems.

So to begin:

Active sensors work by sending out a structured signal specifically designed in such a way as to be indistinguishable from noise so that you know with certainty when you hear an echo(found something). A very good example pretty much everyone is aware of is Sonar. Ping! You make noise, and you hear it echo off the target. Radar does the same thing, but instead of sound, its radio waves, and its quite a bit faster.

This signal needs to be indistinguishable. You don't want random noise generating a spike that looks exactly like a target. Known as the false alarm rate, this is the ration at which the system will falsely identify noise as a target. So you use a structured signal that is just complex enough that the odds of nature every producing it when your listening for it are so low as to be effectively zero.

Thats all well and good, but what about when you have two units near each other with the same system, they'll hear each others echoes and transmissions, and wont know whose echo is whose, and whether the transmissions are targets(since the other guy can hear your transmission, and vice versa) or not. So you need to make the different enough to distinguish.

So you use different frequencies. A radar might be designed with a frequency range from 9.8ghz to 10.1ghz for example. So if you encounter significant interference on 9.85, you switch to something else, like maybe 10.05. Its somewhat more complex than that, but that's sufficient an example. this allows you and many friends to use the same radar near each other without blinding each other with interference.

So that covered, how would a jammer disrupt it:

There are quite a few ways actually, and not all of them are easily tracked.

first and foremost, lets begin with intel. We need to know about our enemy and their capabilities.

If we do not know anything at all, we have very limited choices for jamming.

If for example, you don't know where your enemy is, but you know they are near and they must be jammed, then you cannot aim an antenna at them, as their location is not known. you must instead use an omnidirectional transmission. This hurts your effectiveness since power at the target point is greater reduced, but it allows you to jam a target whose location is not known.

If we do not know their frequencies in use, then we are further hampered. We must now jam a very wide range of frequencies in an attempt to also cover the frequencies they are using. This further hurts our average power at the target, as power is being spend on frequencies other than those used by the target.

Suppose we do know where they are, but we don't know about their systems.

Now you can use a directional antenna to great effect. the antennae might give you, say 35dBsm of gain, well, that's 3162.28 times the signal strength, pretty significant. This allows either that much more noise at the target point, or the same noise at a target point that is roughly 7.5x further away. pretty big deal. This also applies to their sensor. The antenna magnifies their signal, it also magnifies received noise just the same. They also aren't perfect, they still hear some noise from directions other than where they are pointed, but good antenna hear VERY little of such noise. Still, sufficient power will influence the system even when its not aimed at you, this can result in completely blinding the system no matter where it points.

Barrage jamming is pretty inefficient as far as the other types go, so lets up the intel.

Suppose we also know their approximate frequency bands in use.

Now you can focus your power into a tighter range of frequencies. This has advantages other than in jamming as well. if you must barrage jam from 1ghz to 20ghz just to ensure you have an effect on a potential target, then you might be detected by a passive sensor that is sensitive to 4ghz to 6ghz. If your target is only using 9.8 to 10.1 and you know that, so you jam from 9.75 to 10.15, that same passive sensor will not detect your jamming now, as your not using a frequency it is sensitive to.

This tightening of the frequencies increases the noise the target experiences because you aren't spreading it around anymore on frequencies you don't need to jam. Im fairly sure the math is incorrect, but the principle at least is correct: if you had 1Mw of jamming spread across 1ghz your putting 0.1w per hz, if you tighten that to 9.75 to 10.15, your focused into a 400mhz band, 2.5w per hz for a noise increase of 25x.

But what if we know even more about our target, suppose we also know the rotation speed of their antenna?

Older systems must track back and forth predictably. The signal goes where the antenna points, so you listen to their radar, and you can tell its rpm by the detections per minute, since it will only hit you with strong signals when its aimed at you. Phased arrays can electronically steer the beam, so they can aim the signal at points other than where the array is pointed, which can make this impossible to achieve since the hostile radars pattern of painting you might be very random.

Now you can upgrade to spot jamming. Same basic idea so far, but you don't have to spend all of your time transmitting, now you can transmit only when they look at you. This allows you to take advantage of something they might have done in the design of their own ship. They don't really want their passive sensors that detect radar to also hear their target echoes from their own radar, so they might not be sensitive to those frequencies. A simple solution is to be sensitive, but ignore returns on the same bearing the radar is aimed at, so now your jamming might be ignored since your jamming will only be detected when the radar is aimed at you.

A more advanced system will still detect your jamming, as they used a very specific signal structure for the radar, and you're transmitting noise, they are easy to tell apart.

if you know when the radar is aimed at you, its frequency bands, and its transmission length, you can go even better still.

now you can perform sweep jamming in conjunction with spot jamming. This is where you do not continuously jam a range of frequencies, instead, you 'scan' through them with your noise. You do not stay on any one frequency at a time, so you do not completely blind a system, but you also become harder to detect and localise as your noise is not all in one frequency making a nice big spike, nor is it a block of frequencies. You may even cross into frequencies they can't listen to causing them to lose your noise intermittently as well. You could randomly bounce(frequency hopping) from frequency to frequency while spitting out noise, causing interference and potentially making the error correction systems on the target go nuts. This can make the system decide its false alarm rate is too high so its become defective, and throw error messages which can mislead crew into not trusting the output of a good sensor.

Yet we can still do even better. What if we know the target's signal structure as well as everything else?

So now that we know exactly what the target systems transmission will look like, we can offset our jamming by 180° in phase. A quick explanation is in order. Picture waves in the ocean, they are very similar to electromagnetic waves in radar for example. All frequencies do this, all signals do this, you can influence it a bit, square it more than leaving it a smoothly curving peak, but it still must have a peak. A well designed jammer can throw noise that is perfectly inverted, where there were peaks it throws troughs and where troughs it throws peaks. The result is noise. They will still detect something, plenty of power will go back to the radar(you did just double it), but it looks nothing like what they sent out, its noise. They know something is that way, but not how far, or fast. This is the same principle as that behind noise cancelling headphones. And since the noise only happens when the radar is pointed at you, the definitely know a jammer is somewhere in your direction.

Before I proceed to an even better result, i'll diverge with a quick bit of ECCM.

They know you will try these tricks, and so they design radars with some neat features. For example frequency hopping and large bandwidth. The very simply version of bandwidth, is that is the range of frequencies in use simultaneously by a system. For example if the above system were to use 9950mhz as the center frequency, with a bandwith of 40mhz, it would transmit and listen across everything form 9930mhz to 9970mhz. if you can only jam a band that is 20mhz wide, then the best you can do is to blot out half their signal with noise. At best that's only a 41% decrease in their effective range against you if your just throwing noise. If they can frequency hop, they can simply change to 9970 to 10010 for the next pulse and not experience any noise until you adjust to match, then change again when you do. it could be purely random, 9970-10010 one pulse, 9704-9744 the next, and 9872-9912. if they can do that every pulse, you'll never match them without also know how the number generator is picking its pseudo-random numbers, so your stuck with covering a range to hamper them.

Back to jammers.

Suppose you know where they are, what frequencies they can use, that they cannot frequency randomly hop from pulse to pulse, can cover their full frequency range and bandwidth, and know precisely what their signal looks like.

Now you have some neat tricks you can pull. In effect you can talk directly to their radar, and lie to it, because you can now form a signal that looks exactly like that receive wants to see as an echo.

So a little more detail on how they work. In order to detect a target behind another target, use what is called a range-gate. The easiest way to explain it is to think of the radar scanning with a grid. Everything from 100,000meters to 100,005m for example, is maybe considered to be one target, so if it receives two returns that are 4 meters apart, it might not see them as separate targets, it might only see one target that is twice as big, since its detecting two echoes as one echo. the range gate is related to the wavelength of the radar, and its signal structure as there are tricks to improve range resolution. So knowing that, here's the next trick.

Deception jamming.

In deception jamming you have to be very quick, and very capable, and know very much of your target system's specifics. if you do, now you can start lying to it. In effect, you can read their signals to learn what you need to know, for example which direction they are in, maybe how far away they are(by looking at how strong the signal you received is-modern LPI radars can modify that on the fly per target, so its useless there), and where they think you are. This is not worth it if they haven't found you already for certain. there is no point to giving them a good track when they have none and are unaware you are near. The best indication they have found you will be a switch in the radar signal to a firecontrol frequency/pattern, or a sudden increase in the energy directed your way to provide a stronger signal, or more frequently being painted as the radar spends more time keeping an eye on you specifically.

Then what you do is on the next pulse once your ready, you spit back an inverted signal turning it to noise but not quite as strong as theirs. the goal isn't to produce noise at the full strength, but to weaken their signal enough that they lose it in the noise that's already there. Then at nearly the same time you send back a signal that is identical to theirs, but stronger and delayed just a tiny bit. Because you weakened and disrupted their signal, you hope that is dropped, and by giving a signal of your own that is stronger, you hope that is accepted by the system as the true signal. By transmitting a bit after initial reception, you also imply that you are further away than you really are. They can tell sorta where you are by your jamming, but not precisely enough to shoot at with guns/lasers, or to guide missiles to you. the missiles own radar can be mislead exactly the same way, and it will believe you are over there when really your right here and it will miss.

if you possess enough transmission power, you can also mislead them in the other direction, into believing you are closer than you really are because you can make your signal strong enough to be believed as an echo from that close in. You just need to increase your apparent approach rate by gradually transmitting a bit sooner and sooner while turning the real echo to gibberish and trying to keep it from being accepted as a target.

its important to note the doppler effect at this time. Not only does your timing of the signal matter to where the radar thinks you are, but the doppler effect is very important in determining how fast you are, you need to use this to lie as well. the radar is very likely to reject your signal if you move your self 1000m in 1 second, but the doppler says you only moving at 300m/s. The mismatch will be noted, and it will likely follow that very weak signal that you tried to make it ignore, because that still says 300m/s and is where it expected to find it. Your signal was too different to be believed. you gotta take it slow.

Speaking of Doppler, you can also lie about your speed. The radar can track you step by step and work out that its wrong, but a missile is likely to work with what it gets per pulse, which means while you won't defeat a tracking radar, a missile might believe you are moving much faster than you really are, or much slower and use an entirely incorrect lead angle. Coupled with an incorrect range-gate and the missile is almost certain to miss. Still, the missile might only care about bearing, and that can be hard to fool.

there is still one better that can be done that i'm aware of. Its merely the combination of both sweep jamming, and deception. Once you have the radar fully deceived and tracking your ghost return you can start introducing noise in an attempt to make the error correction freak out, and if you can manage it, the system will then paint your track as erroneous and drop it, and because it has stopped tracking your real return and its lost in the noise, you are now effectively gone. its easier to keep a weak track than to find one which is why this works, make it stop actually tracking you by lying to it, misleading it with its own signals, while making yourself too weak a return to be redetected, then break up the ghost with noise and mislead the operator into thinking the system has malfunctioned and make him less likely to trust it until it has been checked and found to be operating fine.

1 to 1, you can screw anyone up right good if you can jam them effectively. they'll be unable to determine your exact position even if the jamming itself can give them an approximate position. if they must rely on a guided weapon at this point to complete the kill since those can be sent to approximate locations and then search on their own, if you can also mislead that, it too becomes useless against you, and in the end, whether they know you are jamming them or not, it matters not because they can't locate you well enough to hit you, they might as well be blind for all the good it does them.

if your capable of achieving enough width, rapidly enough, on enough frequencies with sufficient power simultaneously, say multiple independant jamming systems, or one spectacularly capable system you can simultaneously do this to multiple sensors at once, and blind multiple units, and then even triangulation is ineffective at more than 'somewhere near there', which isn't enough to shoot at. They then need either enough systems to overwhelm your ability to jam them all, a system that operates outside your specialties so they can remain unaffected, or a sensor that can home in on your jamming.

its worth noting your jammer can pull all the same tricks the radar can so that a seeker that's homing on your jamming may need to listen over a very wide range to effectively home in on your jammer since you might be chasing target radars across many frequencies seemingly at random. This means the bandwidth on the seeker may need to be large to accomodate your potential frequencies and keep you detected, this means a lot of noise, which reduces the strength of its detection. if its tightly focused it might not hear much of your jamming and will have difficulty keeping a lock.

of course, you could always stop jamming for a moment to see if the missile switches to an active sensor. If it does, reach into your bag of tricks and lie to it to, it'll keep using the radar not realising its being lied to, and will miss. if it doesn't, resume jamming until you must stop to blind the weapon, then maneuver. they'll get a good lock, but your distant, they'll need time to hit you, you need only a few moments to evade, then resume jamming efforts.

To put the ball back in the radar's court, AESA(active electronically scanned array) systems make much of this useless. They can almost as a rule frequency hop at random, they can steer the beam allowing for randomising the time between transmissions aimed at a given target, they can use potions of the array for different tasks simultaneously allowing for directing energy at more than one target, or at the same target on very different frequencies or patterns, or to be a jammer and radar in effective operation simultaneously, and they can vary the power output so that the signal is never stronger than it needs to be. These can make detecting the system incredibly difficult, and predicting it near impossible. if you can't predict it, you can't deceive it, nor cancel it, nor effectively counter it with noise on the same frequencies without covering a much wider band.

They aren't immune to the above techniques, just very capable of working despite them.

I'll approach the ending with a word on passive systems.

These are troublesome. they never give you anything, and use what you give them against you. it doesn't much matter what you give them, because its always something. There are few ways I am aware of to deal with such systems.

Barrage jamming it with so much noise it cannot find targets. But this leaves a great big spike in the right direction, and if you can't throw energy down the bearings of multiple sensors, you can't blind them all, and they only need them to cross to know sorta where, and two to cross that aren't jammed to know exactly where. Your problem is know where they are, because they are passive, they give you nothing to help you find them unlike with radar that must transmit first.

ideally you will know what range to expect them to be able to detect you, and shortly before that you blind them. they are going to know something is over there in a moment anyways, why let them know who, what, or how many?

Depending on the system, and how it functions, it may be possible to flood it with false positives much like with radar, but being a passive system, they don't really care what they see, just so long as its something much of the time so good luck with that.

I think this is the concept behind IR jammers, they paint the seeker head of a missile with the laser and watch the scintillation of the return then try to keep the laser painted on the same spot on the seeker head to mislead the missile as to where it needs to go. Since the point is off center, it thinks it needs to turn, and with tracking the seeker head, it continues to turn and then loses the original target entirely.

For example, turning left and climbing while painting the lower right of the seeker head so it dives and goes right. Timed right it might be unable to correct and hit you even if it never did lose sight of you.

Lastly, your left with burning it out. if you can throw enough energy at it, you can potentially damage the electronics which are very sensitive and may not be able to handle it, which is a semi permanent solution to the problem. An array will fail gracefully, which means as pieces fail capability diminishes rather than an abrupt termination of function. Think of that like the pixels of an LCD dying one by one instead of the whole screen crapping out in one instant. Diminished sufficiently the result is the same as effective jamming, but considerably more effort is required.

I'll end with:

this makes it seem easier than it really is, but if you have a significant technological advantage, or excellent intel, you can make their radar operators go crazy. Old jammers have almost no hope of even interfering with a modern system let alone successfully jamming it in any way thats useful, and old radars have an equally dim chance of coping with modern jammers. When your on equal footing, the possibilities are endless.

Given that radar is nothing more than an active electromagnetic energy detection system with limits on its spectrum, i would wager that these principles will apply to any system in the near future, possibly also distant future that also uses electromagnetic energy as its medium, and relies on transmit/receive as its method of operation.

purely passive systems are your problem there

And finally, im 100% certain the militaries of the world have quite a few tricks no one has ever heard of.

Edited January 16, 2014 by Amram
finsihed a sentence I derped and forgot to write the rest of.

[Ignamious]

Amram, Great post! and your spot on, on almost everything! and your right, everything you said was pubic info... i had to double check with Barrage, but thats out there too.

One thing to note. Its VERY VERY VERY hard to burn out passive systems... any engineer will build inhibiters into the system. Also, Phased arrays are pretty much the new system so you can't track a "Dish" anymore in space you will NOT!!! use a spinning object. Spinning objects in space create torque, and that creates forces that you must counteract. Assume in space you will only ever use phased arrays, with redundant backups, all hardened with safety shunts and inhibiters.

as it stands now, you can get self attinuating devices to reduce the incoming gain.

Dodging IR is easy. a "hot spot" brighter then you / your engines is all you need, both long wave and medium wave IR can get overwhelmed by it, and the IR missile with track it instead. Look at a flare. Who knows in 200 years we might have better IR but chafes are we'll have better targeting capabilities then that.

( i had to use so much google fu >.<)

[Amram]

flares aren't a very successful answer against modern seekers. The problem lies in what are sometimes called two color seekers, or rather, those that can use both long and short wavelength IR.

The long wavelength, 3-5µm is the more common, and has been in use since the beginning, and this is what flares fool with relative ease. in fact, early sidewinders were known for deciding they liked the sun as a target better than whatever they were shot at. These are limited to tail shots though, as they require a very hot source to home in on.

More modern seekers can use the short wavelength IR frequencies, from 8 to 13µm, and this allows them some seriously upgraded capabilities. For one they can detect the difference in temperature between the surrounding air and the targets skin. These are what allowed for all aspect missile shots, since they don't need to see the hot engines to lock on, they can see all they need easily enough from any angle.

Flares can be made to trick the 8-13µm wavelength seekers, but those are near always paired with the 3-5µm wavelegnth capability as well, and fooling both in one flare is nearly impossible.

Worse still, truly modern seekers use what is known as IIR, or imaging infrared, they don't just see a hot spot, they see shapes, they know what a plane looks like, and flares aren't it. These seekers are especially dangerous given that they can selectively hit whatever part of your aircraft they want to. Want to put the missile down the intake, you can do that, if your missile is agile enough and the angles allow for such a shot. Want to always aim for the pilot, you can do that too. Prefer center of mass, that's also doable, and even though its offset from the significant head sources, its usually pretty easy to determine where that is.

For example, this is from an AIM-9X seeker during testing. if they'll share this much, i'd wager it can do considerably better now

AIM-9x, Iris-T, Python-5, AAM-5, or R-73, either of these decides it likes you for a target and you have some seriously huge problems, because flares are iffy at best, useless at worst. There's a reason why you throw lots and lots of flares in the hopes even one provides a good decoy. if you think you've thrown enough flares, throw more.

regarding dishes vs arrays, keep in mind that sometimes an array is straight up overkill and definitely far more expensive. This may not be sufficient deterrent, but i'll provide an example. a firecontrol illuminator. They generally only need to light up one target at a time, and they need to light them up real good so the weapons being launched can see it.

To be fair though, things only get cheaper with time, and beyond a certain point, the cheaper dish isn't really that much cheaper to warrant giving up the strengths of an active array, so I can see the dish finally dying out. I wouldn't see a near future spacecraft with only arrays in use as unrealistic. maybe a tad more expensive than it needs to be, but, unlike with ships, I don't think the radars will be a major part of the cost. Currently the electronics suite of a combat ship can actually exceed half the total cost of the ship. The cost of building a ship in space might change that balance significantly.

Agreed on burning out sensors. its not easy. Pretty much the realm of lasers, or giant emitters with high gain focused on a small little receiver that simply cannot deal with the power its being given, think SPY-1 or bigger putting everything it has into something as big around as your head at ranges of less than 10km. Issue there is that you need the average power to get out of hand.

Radars and ESM's are designed to handle pulses, but if you can get the sustained energy level above what you it can cope with, you can damage it. I don't know near enough to hazard a semi accurate guess as to the ranges and power levels that would take, but I suspect if any modern system can do it, it'd be SPY-1. Brute force and a tightly focused beam, its the magnifying glass of radars. 6000 times more power than your microwave, and it can focus that into a spot the size of your microwave.........I think the only question is at what range can it fry electronics as opposed to whether or not it can.

Off topic but neat fact. They actually had a problem when they first started using the SPY-1 system. it was too good. Seriously. It was tracking non-targets, such as insect swarms. Aegis automatically detects and marks tracks, so the operators pretty much had to tolerate this until an 'upgrade' was rolled out to stop that.

Edited January 16, 2014 by Amram

[PTNLemay]

I do appreciate all the content you've added to the discussion Amram, truly. Unfortunately it might be quite easy to overlook on account of this

I will also skip passive systems.

As you mentioned, all of that is applicable to active scanning, and unfortunately that might not be what we use to scan space for enemy ships. Passive scans will probably be enough to detect engine IR signatures and stuff like that from very far away. Hence why I was initially thinking of an IR beam to confuse the enemy sensors.

I don't have any big complicated specs sheet like you've accumulated, but I do have a real world example in the WISE telescope. This was a telescope launched some time in 2009 tasked with scanning the whole sky in infra-red. You can see some of it's contributions towards the end of this video

In the end it observed over 100,000 objects and discovered some 33,000 new asteroids. I'll acknowledge I'm no expert on optics, but I strongly suspect that this technology (which is all passive) could easily be adapted to scan space for enemy spacecrafts. THESE are the kind of sensors I want to jam, because I suspect they would be most effective over the long distances you'd typically see between points of travel.

Some more fluff about WISE: http://en.wikipedia.org/wiki/Wide-field_Infrared_Survey_Explorer

I actually don't know what the smallest asteroid discovered by WISE was... if it's something like 50 km, then a point could be made that maybe human spacecrafts might just be too small for this technology to detect... I'm not sure.

[meve12]

Somewhat unrelated, but suppose you had a small tactical nuke and a lot of chaff. Could you use the nuke to heat up and disperse said chaff? You'd end up with a very hot cloud of chaff as well as the usual flash. Might be useful as a "smokescreen".

[Scotius]

https://en.wikipedia.org/wiki/2013_YP139

Newest asteroid found by WISE - 650 meters, and it is very dark. Coal dark. Any ship with active systems (thus radiating heat) will be much more visible.

[Amram]

A modern military example or a passive IR sensor:Vampir MB. it passively detects hostile threats to the ship, but its range is dwarfed by the radars. In space it might outperform a radar since it would be freed from atmospheric absorption of IR energy. Then again, the radar would also be freed of atmospheric absorption.

Passive systems do allow for triangulation, but for one unit that is alone, its hard to achieve enough angular separation between the sensors for good triangulation, and if you can't, then target motion analysis can provide a good estimate, but that takes time, and every time your target maneuvers, or you maneuver, the TMA solution goes out the window. which in active combat may make it useless. its hard to say how like submarine warfare space warfare will be. i think it'll be more akin to combat between surface ships than subs personally, other than the three dimensional maneuvering obviously.

If all you have are passive systems, you will be hard pressed to put up a real fight one to one I think. Your opponent will be able to locate you with the same precision from greater range in less time, even though this may give his presence away. Unable to accurately and very rapidly determine range, its almost impossible to judge the target speed and how much lead your weapons need.

To be fair, of course you could have your ships stay in groups and triangulate together. Your accuracy will still be less than with an active sensor given the techniques that can be utilised to improve resolution beyond what wavelength alone can provide, but it may be sufficient for combat.

So, consider that you know your target relies on IR to see you much as you do to see him, how important will reducing IR signature be in the design of new ships? A specially designed canopy or plating at the front of the ship, with an active cooling system to manage the temperature and as a result the difference to your surroundings could result in making the craft invisible to an IR only sensor. Given that IR is line of sight, they could have enormous radiators hidden away behind a thermally controlled canopy. From the side or behind, you couldn't miss their approach, from the front they are impossible to see as line of sight only allows you to look at the thermally controlled surface of the canopy, which near perfectly matches its surroundings.

Then there's tricks like approaching with a star at your back to hide in the emissivity of the star. you may need to actually increase your own emissivity to match so that you don't become a dark spot to an IR sensor.

Or killing a ship that's known to be planned to go to you, and jamming their communication attempts to alert you. you detect a craft approaching at the right time, and by the time you can see that its not who you thought it was, it may be too late to adequately respond to the attack. kinetic weapons launched at a facility from long range are such a situation.

Just communication alone may be reason enough for jamming to be alive and well, and still very useful since it is a send/receive type of system

I think relying solely on passive systems would be asking to get blindsided. Instead i think its more likely that active systems will still have their place to work in harmony with the passive systems.

Defeating EM emissions is challenging, but doable. Defeating IR is challenging, but doable. Defeating both is exponentially more difficult than merely defeating one or the other because the constraints of designing for one will interfere with those of designing for the other.

Given the technical difficulties involved, and which systems will see the most use, I suspect that ships will find themselves more focused on IR stealth, with dedicated EM warfare vessels still in use to deal with those instances where active systems must be dealt with, and some degree of EM warfare built into every craft, much as it is with ships today.

All that said, i do think IR, and other passive systems will take over for early warning. they won't be perfect, since they'll have exploitable weaknesses, but if your target is 8 light-days away, then an active system needs at minimum 16 days to alert you to their location if your turn it own now, or 8 days if it was on at this time 8 days ago so emitted radiation is arriving there now, while a passive system may alert you this very moment if they have been within your detection range for more than 8 days.

Edited January 17, 2014 by Amram

[DerekL1963]

Somewhat unrelated, but suppose you had a small tactical nuke and a lot of chaff. Could you use the nuke to heat up and disperse said chaff? You'd end up with a very hot cloud of chaff as well as the usual flash. Might be useful as a "smokescreen".

No, there would no significant flash at all - the flash of a nuclear weapon is a product of the reaction between the bomb's energy and the Earth's atmosphere.

[DJEN]

Minovsky particles. They have a decay period of 28 days, and decrease the energy states of photons.

They also absorb them, too.

[palker]

This how you jam sensors in space.

[DJEN]

This how you jam sensors in space.

-vid-

Mmm......... Raspberry...