Main Function of Jammer Pods?

[shehbazi2001]

this post is for my own understanding and perhaps for others too....

what are main fuctions of a self-protection jammer carried by military aircraft like ALQ-131 or 184?



possibly,



(1) to jam the ground-based radars of a SAM battery



(2) to jam the radar of opposing fighter



(3) to jam the radar-seeker of an incoming active-seeker BVR AAM like AMRAAM or seekers of active-radar guided SAMs.



(4) to jam the radio communiction of pilot with other planes or with ground controllers.



(5) to jam the radio proximity fuse of the SAM or AAM?



(6) can the chaff trigger a radio or laser-based proximity fuse of heet-seeking or radar-guided AAMs?





My own opinion,



(1) the airborne self-protection jammer cant jam the ground-based SAM radars and thats why aircrafts carry chaff catridges. SAM radars are understandably more powerful that airborne ones and power is important especially when it comes to noise jamming technique. If AESA radars are integrated with SAMs, then even special EW aircraft will find it almost impossible to jam with current known techniques.



(2) From Iran-Iraq war events, it seems that its possible by some ECM pods. Radars of Irani F-4E Phantoms were jammed by some Egyptian Mirage-5SDEs supplied to Iraq and equipped with ALQ-234 ECM pods. At the same time, the AWG-9 radar of Iranian F-14 Tomcat remained immune to jamming by this pod.



If Pakistani and Indian fighters jam each other radars from standoff ranges, BVR combat may not be possible and things will come back to old turn and burn dogfight.



With the arrival of AESA radars in fighters, ECM pods will find them extremely difficult to jam. Keeping in view that the Indian PHALCON is not just an AEW aircraft and perhaps may be used to jam the traditional radars of F-16s, we should consider AESA radars for at least those F-16s that are still waiting to be delivered or refurbished.



(3) To me this should be the main function of a self-protection jammer. If we conclude that an ECM pod can jam or degrade the active radar-seeker of an incoming SAM or BVR AAM, then the semi-active guided SAMs seem preferable in contrast to active-seeker ones. S-300 also I think uses semi-active guidance. I may be wrong but that what I conclude here. A active-seeker having brilliant ECCM can be thought to survive all jamming,eg the success of AMRAAM may be attributed to ECCM features embedded in it.





On the rest of points, I am not sure and professionals can give some explanation.

 

[shehbazi2001]

An aircraft (or helicopter or UAV ) uses various electronic systems like radar altimeter, radio comm, weather/navigation/terrain following/AI radars, GPS receivers......all using electromagnetic spectrum........but to avoid interference, they all use different frequencies/bands.........for UAVs, the uplink and downlink with ground-station are add-on elements, minus the radio.

If we add a jammer onboard a fighter, that means it must also not interfere with radio, radar(s), altimeter, GPS receivers etc........

Therefore it seems there is a limitation on jammer, that it should not jam those frequencies which its own aircraft is using............may be of its own radio, its own radar.....

Hence we can conclude that if we come to know the frequency-range of Su-30's radar.......we can be sure that their AWACS or the jammers carried by Su-30 shall not jam those frequencies......and then we can tune our own radars to that frequency.......this way it shall be safe from JAMMING......;

Also an automatic system can be installed in Saab-2000 AEW that finds in real time the frequency range of Su-30's radar or other intruding fighter's radar frequency (if they are using it and not in radio-silence, however for BVR shot at least one aircraft shall switch-on the radar) and then relays it to other aircrafts using safe link........

 

[Awesome]

Much like radars, the Jammers cant also be directional?

 

[shehbazi2001]

I dont think so.......if we see the pics of ALQ-131 or 184, the antennas are mounted all around it.......to provide full coverage........

but thats what seems to me.......definitely the view of an electronics engineer working on such systems would be beneficial.....

I discussed it with some electronic engineers but we are very unfortunate that our guys are mostly not interested in military technology.....they normally dont go outside the university books unless its their job.....

 

[x_man]

With few exceptions, generally deception jamming technique is employed against acquisition, tracking and AIs radars..…..and noise jamming is usually used against surveillance radars….As you have stated about chaffs, it is also one of the passive deception techniques…BTW in last decade or so, and Jamming Chaffs are also available in the market…..More bad news for the Air Def guys….

The active noise jamming is very versatile and barring few limitation, it can be employed against most of the communication transmitters , early warning hi level radars and data links…If transmitters frequency is know: well and good and spot jamming will be used ,but if transmitters’ freq is unknown, then heavy duty barrage jammers can be employed……..the disadvantage of barrage jammers is that their power is diluted as they might be jamming the whole band…..

The whole EW field is so dynamic that the day you buy a jammer, very next day its ECCM technique is out….its just like Spy Vs Spy……..As far as the South Asia’s electronic battle field is concerned, I think we are doing pretty well in exploring the EM spectrum….We have the capability for soft kill, may be its time to acquire some toys for Hard Kill (anti radiation missiles)

 

[shehbazi2001]

While in my first post in this thread I mentioned that an airborne jammer cant jam the SAM radars, I want to add that an airborne jammer can degrade the performance of ground radars so that it can not get a lock on the aircraft.

But as the aircraft goes near to SAM radar, then the ground radar "burns through" the jammer (perhaps due to more power) and then it can get a lock of aircraft.

So the jammer can reduce the effective range of the ground or SAM radars.

All this is true for an aircraft non-specialist of Electronic Warfare (EW) and just carrying a self-protection jammer.

 

[Tang0]

Does the PAF have a dedicated ECM platform like the prowler? It seems a bit of an overspecialization for such a small force, but I seem to recall the F-16 had a ECM/EW specific variant.

 

[shehbazi2001]

Although I am not in Air Force, but I think there is no EW specialist aircraft like Prowler.

But Prowler does not emit jamming signals from its nose or its belly, Prowler carries two jammer pods, each one more powerful than a single pod of the fighter aircraft like ALQ-131 or ALQ-184.

This means that an ordinary fighter aircraft can increase its jamming power by carrying more than one jammer pods.

If an attack formation is lead by a single F-16 equipped with two or three jammer pods (instead of bombs), the effective range of the SAM radars can be reduced. Thus a mini-EW aircraft can be made.

This may not be as effective as Prowler because Prowler has also the systems of processing and identifying the radar signals that it receives and then emitting the jamming signals in accordance with those received signals.

Still, the avionics and radar specialists of PAF can work on this project and for a start they can link a RWR with the multiple jammer pods (normally RWR is attached to a single pod) and see the increase in the jamming power themselves and then fine-tune it further in light of the results.

 

[blain2]

With few exceptions, generally deception jamming technique is employed against acquisition, tracking and AIs radars..…..and noise jamming is usually used against surveillance radars….As you have stated about chaffs, it is also one of the passive deception techniques…BTW in last decade or so, and Jamming Chaffs are also available in the market…..More bad news for the Air Def guys….

The active noise jamming is very versatile and barring few limitation, it can be employed against most of the communication transmitters , early warning hi level radars and data links…If transmitters frequency is know: well and good and spot jamming will be used ,but if transmitters’ freq is unknown, then heavy duty barrage jammers can be employed……..the disadvantage of barrage jammers is that their power is diluted as they might be jamming the whole band…..

The whole EW field is so dynamic that the day you buy a jammer, very next day its ECCM technique is out….its just like Spy Vs Spy……..As far as the South Asia’s electronic battle field is concerned, I think we are doing pretty well in exploring the EM spectrum….We have the capability for soft kill, may be its time to acquire some toys for Hard Kill (anti radiation missiles)

On the topic of hard kill, I believe PAF is looking into converting SD-10 into this type (ARM) of capability. This was mentioned by AVM Shahid Latif a while back.

 

[blain2]

Although I am not in Air Force, but I think there is no EW specialist aircraft like Prowler.

But Prowler does not emit jamming signals from its nose or its belly, Prowler carries two jammer pods, each one more powerful than a single pod of the fighter aircraft like ALQ-131 or ALQ-184.

This means that an ordinary fighter aircraft can increase its jamming power by carrying more than one jammer pods.

If an attack formation is lead by a single F-16 equipped with two or three jammer pods (instead of bombs), the effective range of the SAM radars can be reduced. Thus a mini-EW aircraft can be made.

This may not be as effective as Prowler because Prowler has also the systems of processing and identifying the radar signals that it receives and then emitting the jamming signals in accordance with those received signals.

Still, the avionics and radar specialists of PAF can work on this project and for a start they can link a RWR with the multiple jammer pods (normally RWR is attached to a single pod) and see the increase in the jamming power themselves and then fine-tune it further in light of the results.

This is the whole concept of strike packages. Even PAF is employing the Strike Package concept where some MR aircraft with active/passive jamming pods would be able to provide EW capability for the entire strike package. I know of some exercises where more than a few dozen aircraft have been integrated into strike packages.

 

[vizier]

It is extremely difficult to jam a fighter aesa radar but it is again extremely difficult for a bvr missile sensor with low power battery to not to be jammed by some current and emerging ecm systems.

Main function of pods is against bvr a2a missiles. If it is home on jam towed decoys do the job.


Another effective measure is cross eye jamming against monopulse bvr seekers which is getting stronger with constantly improving drfm techniques. Wingtip cross eye pods would protect JF 17 and J10s from amraams.

I think the probability of aesa equipped bvr missile is low as apart from cost considerations
it won't have a high erp or lpi ability with a few tr modules and this can be used as a jamming weakness by powerful fiber optic towed decoys and drfm systems.

For wvr infrared imaging missiles what about considering smoke screens. I mean a rocket carried by a J10 can make a phosphorus trail that would block any optical and infrared signature behind for a period of time. What the plane needs to do is after a2a missile launch is detected launch the ir smoke trail rocket and put the phosphorus trail between the coming ir missiles and itself to break the lock? Just a question as this depends on the blocking capability of the smoke in ir band. Then perhaps the good old days of dogfighting will start again.

 

[shehbazi2001]

It is extremely difficult to jam a fighter aesa radar but it is again extremely difficult for a bvr missile sensor with low power battery to not to If it is home on jam towed decoys do the job.

If BVR AAM resorts to home-on-jam, then towed decoy would do the job? I dont think so. If the jammer can be towed behind the aircraft, then this may be possible.

I think the probability of aesa equipped bvr missile is low as apart from cost considerations it won't have a high erp or lpi ability with a few tr modules and this can be used as a jamming weakness by powerful fiber optic towed decoys and drfm systems.

You are right but HAVE DASH program for AIM-120D seems to be aiming for the same thing.

For wvr infrared imaging missiles what about considering smoke screens. I mean a rocket carried by a J10 can make a phosphorus trail that would block any optical and infrared signature behind for a period of time. What the plane needs to do is after a2a missile launch is detected launch the ir smoke trail rocket and put the phosphorus trail between the coming ir missiles and itself to break the lock? Just a question as this depends on the blocking capability of the smoke in ir band. Then perhaps the good old days of dogfighting will start again.

Idea seems to be worthy for testing.

 

[qsaark]

This is the whole concept of strike packages. Even PAF is employing the Strike Package concept where some MR aircraft with active/passive jamming pods would be able to provide EW capability for the entire strike package. I know of some exercises where more than a few dozen aircraft have been integrated into strike packages.

EA-6B Prowler typically carry three EW/ECM pods in addition to what is housed in the tail fin etc. The pilot is accompanied by three electronic counter-measure officers who attend to the radar detection and counter-measure units housed in the pods under the aircraft and at the top of the tail. Due to the work load, three additional crew members are required. F/A-18G, that is going to replace the EA-6B, also has an additional crew member who manages the EW/ECM. Technically our F-16 B/Ds could be modified for the said role, but I have not seen any F-16 ever been used as dedicated EW/ECM platform.

 

[qsaark]

Prowler carries two jammer pods, each one more powerful than a single pod of the fighter aircraft like ALQ-131 or ALQ-184.

This means that an ordinary fighter aircraft can increase its jamming power by carrying more than one jammer pods.

More correctly, more than one type of jammer. For instance, both the EA-6B and the EA-18G carry two AN/ALQ-99 high band (Band 9/10 transmitter) jammers and one AN/ALQ-99 low band jammer (1-3 Band Coverage).

 

[qsaark]

I dont think so.......if we see the pics of ALQ-131 or 184, the antennas are mounted all around it.......to provide full coverage........

Interestingly, this is also the downside of the current jammers. Since the current pods rely on antenna to relay the energy, the energy 'spreads', not 'directed'. US navy has recently invited companies to design the 'next generation' jammer systems for the EA-18Gs.

US Navy starts next-generation jammer bidding war

Flight International. 03/02/09

By Stephen Trimble

The US Navy has selected four companies to participate in a four-year, $430 million competition to design a next-generation jammer (NGJ) pod for the Boeing EA-18G Growler and Lockheed Martin F-35 Joint Strike Fighter.

BAE Systems, ITT, Northrop Grumman and Raytheon have each received a $6 million contract to begin developing their concepts for replacing the 38-year-old ALQ-99 pod. The navy favours a solution based on an active electronic array, but is not constraining any approach the bidders might take to achieve the desired results.

"We've told them what we want, but not how to do it," says Capt Steven Kochman, the USN's programme manager for NGJ. All four companies are seeking to be chosen for a 10-month technical maturity phase scheduled to begin in March 2010.

The USN is not required to eliminate any of the bidders, but Kochman says he expects cost considerations to cut the competition to two or three teams. Those will be selected to enter a technology development phase in January 2011, during which prototypes will be demonstrated. The goal is to select a single contractor to finally develop and produce the winning system, which is scheduled for delivery from 2018.

The NGJ effort began in dramatic fashion. After receiving a classified briefing on future threats last year, Deputy Secretary of Defense Gordon England ordered the navy to launch a replacement programme for the vacuum tube-era ALQ-99. The replacement pod is expected to fill the same role: escorting stealthy and non-stealthy tactical aircraft to the edge of the threat zone, jamming the radars used by enemy forces to fire surface-to-air missiles.

However, as a new generation of longer-range SAMs is deployed, the NGJ must adapt with a more powerful and dramatically more precise transmitter, Kochman says. "The aperture on the ALQ-99 is one of the most significant limiting factors," he notes. "It doesn't have the ability to direct it exactly where you want. [Instead, the antenna] spreads the energy at times you don't want, which limits your interoperability."

Although the SAM threat is changing, so are the targets. The ALQ-99 was designed to protect the McDonnell Douglas F-4 and the Vought A-7. But the NGJ will have the benefit of being designed to protect far less vulnerable fighters, such as the Boeing F/A-18E/F Super Hornet and F-35, Kochman says.

The precise requirements to guide the technology development phase will be derived from a 15-month analysis of alternatives, which is under way. But industry teams are already forming for the requirement. ITT, which has purchased ALQ-99 maker EDO, has teamed with Boeing, combining the USN's incumbent supplier for jammer pods and the integrator for one of the first jamming platforms.

US Navy starts next-generation jammer bidding war