Iran deploys passive radar system

During the annual military parade to mark the outbreak of the 1980-88 Iran-Iraq war, the Iranians unveiled a new phased array, passive radar system. It's been dubbed "Silent Radar System", and uses no active emissions, making it impossible to detect.

According to Iranian officials, it's capable of detecting stealth aircraft and cruise missiles. The system is also mobile and can be moved and set up quickly.

This is the second stealth detecting radar that Iran has deployed. The first was claimed to have a range of over 680 miles, and supposedly was capable of detecting stealth aircraft, aerial targets, and low altitude satellites.

Despite this system, an F-22 was able to fly undetected around two Iranian F-4s earlier this year.

On Sunday Sept. 22, 2013, during the annual military parade in Tehran that marks the anniversary of the outbreak of the 1980-88 Iran-Iraq war, Iran displayed a new indigenous passive phased array radar system for detecting stealth targets and cruise missiles.

According to Iran’s FARS News Agency, the radar systems was developed by the experts of Khatam ol-Anbia Air Defense Base in order to detect fast moving targes at any altitude and speed.

The tactical radar system has been dubbed “Silent Radar System” because it acts passively: it does not emit any radar wave and can’t be detected by the enemy systems.

Furthermore, it can be moved quite easily and can be installed in a short time.

Commander of Khatam ol-Anbia Air Defense Base Brigadier General Farzad Esmayeeli said “The radar is capable of detecting stealth (radar-evading) targets and cruise missiles and enjoys a high movement and mobility capabilities and acts in different ranges,” FARS reported.

theaviationist.com...

Sounds a bit like magic to me...

reply to post by Zaphod58


Hi Zaphod, If I were the Iranians and I had this capability I would not let anyone see it until it was time to let loose the dogs. I am thinking of Coventry in WW2.

Do they have this? Your guess is as good as mine. To suggest the Iranians can not come up with something new and startling (and you haven't) is just silly . The Iranians have had their own defense industry for a long time. I just don't know and I think no-one will until the missiles start flying.

History teaches us one thing. Do not underestimate the Persians.

P

reply to post by pheonix358


I agree, but at the same time, the last thing you want to do is let your pilots get jumped like those F-4s did. If the F-22s decided they were hostile and were a threat to the Predator they could have opened fire, and the F-4s were dead.

I have no doubt that this system would work well against conventional aircraft, but short of getting their hands on some RAM from a late generation stealth aircraft, I don't see how they could know if it would work. As someone said in another thread, radar is constantly evolving, but at the same time so is stealth. That's what makes the game so interesting.

Good for them. Why shouldn't they have a way to defend themselves? It's not like they don't have to worry about war mongers, invaders, tyrants, and occupiers; and then there are the surrounding Persian countries that may pose a threat.

Ignore post - just read a wiki that explains that passive RADAR does not mean that no radio sources are used, just sources that arnt part of the detector array

Zaphod58
This is the second stealth detecting radar that Iran has deployed. The first was claimed to have a range of over 680 miles, and supposedly was capable of detecting stealth aircraft, aerial targets, and low altitude satellites.

Despite this system, an F-22 was able to fly undetected around two Iranian F-4s earlier this year.

Anything we are told via official channels is simply part of the circus routine. Keep the mob's attention. Keep them cheering and waving the flag. Top Gun showdown ... news at 6pm. Rah, rah.

Back in June, Turkey sent an F4 to to probe the air defenses of Syria and it was promptly shot down. Assuming this F22 event happened at all, what make you think that Iranian defense forces were not watching this F22 and drone interact with it's NON-combatant aircraft? What makes you think that Iran could not hose that F22 and drone with ground-based, computer-controlled laser? (Better look it up before you answer.)

Someone remind me please .... just how many centuries have elapsed since Iran engaged in **aggressive war** on another country? Something like several hundred years? So ..... who are the real aggressors in the middle east today?

reply to post by Zaphod58


Zaphod, you are a smart fellow, and you have some extensive understanding of these matters from the avionics end, so I must ask for your opinion. Do you believe that this invention is real, and/or actually works, or do you think this is the geopolitical version of puffing out ones chest, and giving it the big I Am?

Yo, ZAPH! (tosses bag into the corner) I'm back! Woot! Six weeks TDY (more or less) and I have retoined! You are the first post after my long absence. (dusts red dirt off of boots)

Anyways, what, you may ask, could this be? Well, it's sort of short on details, and the picture is somewhat unrevealing. It looks like a linear phased array of very few elements.

These guys tried to buy a set of Tamara from TeslaPar not too many years ago, though, and were begging the Rooskies for their equivalent. So it's likely one of two things - it's a receiver node in a multistatic radar network, or it's looking for stray emissions from the target.

Given their claim of super-dooper range, I'm betting it's a passive emissions sensor. So, they're looking for your Low Observable Aircraft to emit something, and they're trying to find it by changing their perspective by scanning across the dish with their little feedhorns to get some parallax info. In this case, it's sort of analogous to a hydrophone on a sub.

Even low observables have emitters. In the case of a drone, it's returning anything from position and flight data to imagery. You want to squirt all that skyward, and most of it goes that way, but if you've got a dandy receiver, you can often catch some stray emissions. UAVs are bad about that. LO aircraft less so, however, they still leak some of the stray noise from clocked electronics on board. You can never make that zero, but you can try to stomp it into the noise floor.

Wright Pat has been working on a fighter based passive system for about (checks watch) a year now. In their case (*coffTeledynecoff*) won the bid, and they're off looking at a combo stray emissions parallax tracker with delusions of multiphasic capability. I think DARPA might have bid the same job out in drag.

Iran seems to come out with a new advanced weapon system every week. They show it off and then shove it back into props department so they can make up something else.

The key part is passive detection. If they deployed counter-measures to effectively neutralize incoming air traffic/aerial objects then there is a cause for pause. Otherwise everyone should take a deep breath and calm down!

At any rate, to wax effulgent (I been reading my dictionary - it got that boring), there are any number of ways to defeat low observability, only most of them are really hard to do. So you've got to weigh the likelihood of someone's claim on their innate techno-prowess.

A few examples:

1) The old use a bigger hammer technique: it's not that most stealth doesn't reflect at all, it just doesn't reflect that much, so your radar system edits out the return as being a bug or something due to the low RCS. So what you do is, you firehose a wad of power at the sky, with a cleverly tagged output. This is what AESA's "burn through" mode does. You count on the other guy's LO technology to actually reflect enough for AESA to pick it up, un-bollox the return based on the tag, and carefully look at it to see if it IS a return and not a bug. Mostly, bugs are too small to reflect well at most radar wavelengths. So you do some clever chirping and FM diddling once you see what LOOKS like a return, and if it responds to bigger wavelengths than a bug would reflect, you mark that thing a LO craft and track it. It works, but you've got to have a way agile system to do it, and one with a lot of processor power and CW output. AESA qualifies. AESA can defeat most anyone's LO technology within a dogfight area. Although they don't talk about it.

2) Use a WIDE range of frequencies: the very transparent elephant in the room is the often rumored UWB non-observable radar. It's the gold standard, if you had a craft with one on. UWBs are not yet known, really, although the basics have been around for years. Impulse UWB in a fieldable radar is TOUGH. However, we've got one flying around, and have had for (checks watch) about three years. It's even got it's very own AN designator, and I can tell you that because Kirtland's spiffy medical flight surgeon group blew that little project on the base newspaper. I didn't see where anyone archived that little tidbit, I reported it the second I saw it and no I won't post the article. They were concerned about the effect of UWB emissions on groundcrew, so they named off the project, described the system and what not. UWB smears its emissions over a theoretically infinite range of frequencies, in practice if you can do it over about 500MHz you've done ok. The cool part is that if you do it really well, there's no one spot you can look at it and say "Hey, there's a signal!" so you're essentially unobservable. It raises the local noise floor a fraction of a db. Since it's blasting across the spectrum, UWB finds the places where your RAM and internal structure just don't cut it. A lot of 'stealth' technology is only good for a certain range of frequencies, whatever the designers thought the system would have to foil. So it's not as good as UWB's range. Generally speaking, if you HAD one, UWB could defeat most stealth as well. In addition, there are a lot of neat math tricks that come into play that make your antenna efficiencies go through the roof and whatnot, so it doesn't have to radiate that much total power either. And it gives you some neat time coherency tricks so you can easily find where a target is without timing things. The problem comes in that there was little research/development in that area - you just CAN'T use stock radar equations, so it was start from scratch, more or less. And it's weird and unintuitive, so you have to retrain everyone. But UWB does work, and work well. Especially for stock targets, but it's better than AESA at LO.

3) Multistatic radar - this is the one where you hear about tracking stealth with cell phone towers: Well, yes and no. What it does for you is detect that something is there, mostly. Sandia has a neat trick for imaging planes that fly through the towers with a sort of reverse-SAR processing of the data you probably haven't heard of. Russia likes multstatics. A multistatic array will always detect stealth, even the really good stealth like plasmonic stealth. But it generally only tells you something passed the grid. It's not the sort of thing you can use for fighter direction. I suppose if you didn't alter course and speed after going through the Sandia version you could be vectored in on, but who'd do that?

4) Looking for holes: if you're really good and have ground based systems, you can look up at the sky and look for holes in noise. If you've got a low flying LO, they'll leave a characteristic dip in space noise you can not only spot, but you can get position, vector and speed data from. Can't do it from a fighter though. They can put you on it from the ground, though.

reply to post by Zaphod58


Passive radar is old tech - German fighters use a system similar, with conventional radar.

But, if the Iranians improved its sensitivity...America just needs to attack during high noon...using subsonic speeds. The heat signature, or lack of a distinguishing one, will make the passive system obsolete...or, still obsolete.

TF plus low radar profile plus jamming plus set-it-and-forget-it missiles... They'd be better off with eyes along their border.

reply to post by Bedlam


Bedlam! Dude! I thought they finally sent your ass off on the alien "exchange" program. You know, the one where they fatten you up and eat you after you get there.

I had the feeling that at least one of their systems was more of an ESM type system than a radar type system. Although I had read somewhere that they were looking into the possibility of detecting stealth with a mutli-antenna passive system. Under the right conditions I've heard that it would work. Not WELL, but well enough to at least get an occasional return, and be able to guide something like a fighter in close enough for a visual shot at it.

reply to post by TrueBrit


Yes and no. It's real, and it probably does work, but it's the equivalent of a "something is there" type system. It's not going to let them shoot down an F-22 at 400 miles, but it's going to let them know that they're coming at shorter ranges. It's not going to stop stealth, just make the mission harder to complete.

reply to post by Bedlam


I've heard about 1, 3, and 4. Three worries me somewhat, just because of the F-117 shoot down over Serbia. It seems that sometimes, especially against lower technology opponents, our commanders have a tendency to revert to Vietnam, and the tactics that failed there.

Iran has also announced an "upgraded Sentinel" copy will fly soon.

reply to post by Bedlam


Phew! I was starting to think that ol' framedragged and I had gotten you in trouble again with the big gray 'D' I gotta send you a pm about the IP from PolyMedix...I really lucked out. Anywho, back on topic. You say #3 is effective against plasmonics as well? Isn't that like our bleeding edge stealth tech?

Tajlakz
reply to post by Bedlam

 

Phew! I was starting to think that ol' framedragged and I had gotten you in trouble again with the big gray 'D'

I gotta send you a pm about the IP from PolyMedix...I really lucked out. Anywho, back on topic. You say #3 is effective against plasmonics as well? Isn't that like our bleeding edge stealth tech?

It is. Because the surface plasmons on the structure absorb a lot of the incoming EM. So if you've got a multistatic rig, one side transmits while one or more receive...if you see a dip in the signal at all the receiver sites, something passed between you and the transmitter that DIDN'T scatter the signal. Instant indication it was an LO craft. But...that's all you know. Except Sandia can take a lot of signature data if the transmitter's set up right and get a sort of SAR image of the thing. Which tells you WHAT went through but not where it is now.

Tajlakz
reply to post by Bedlam

 

Phew! I was starting to think that ol' framedragged and I had gotten you in trouble again with the big gray 'D'

Nah, someone got hurt in a car accident and I popped to the top of a short list of alternate technical consults on a system, got an offer I couldn't refuse and wasn't expecting and was out of town for a while. One of those ring ring you just popped to the primary slot tell the old lady yer gone for six weeks be here in an hour click things. Contracting with the USDA rocks sometimes.