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The AIM-9 series of missiles have an infra red seeker head which is passive and cannot be electronically jammed. But the radar seeker head on Active Radar Homing missiles are inherently susceptible to electronic attack, especially the AMRAAM.
Active Radar Homing (ARH) missiles have a radar transceiver which is a device comprising both a transmitter and a receiver. The transceiver on ARH missile has a much shorter range relative to an aircraft’s on board radar and when it comes within range, it locks on to the target or goes active. Until it does, the missile is guided by launch aircraft’s radar.
The Raytheon AIM-120D also referred to as AMRAAM is one of the first of it’s kind to be developed and isn’t terribly advanced when compared to today’s state of the art ARH missiles. It weighs 152kg and measures 3.7m. Radar resolution is based on the size of the antenna. I don’t know the specific size of it’s antenna but apparently it’s smaller than other ARH missiles like the MICA, Meteor and R-77.
The guidance section features an active X-band radar terminal seeker using a solid-state transmitter with a low-side lobe, wide-gimbal antenna, and a built-in radio-frequency processor. The only wavelengths the AMRAAM operates in is X-band frequency range of 8–10 GHz which is easy to jam by the DRFM capable Sorbitsya and the new KNIRTI jamming pods carried by Flanker variants.
The KNIRTI L175M Khibiny M jamming system uses multiple techniques including DRFM and spot-jamming, which the AMRAAM is particularly susceptible to.
DRFM (digital radio frequency memory) jamming, or Repeater jamming is a repeater technique that manipulates received radar energy and re-transmits it to change the return the radar sees. This technique can change the range the radar detects by changing the delay in transmission of pulses, the velocity the radar detects by changing the doppler shift of the transmitted signal, or the angle to the plane by using AM techniques to transmit into the side lobes of the radar.
“Even with six AIM-120's in the F-22, sometimes it is not enough,” one senior Air Force pilot told the National Interest. “The Pk [probability of kill] of those missiles is low against a DRFM jamming fourth gen+ threat.”
“We—the U.S. [Department of Defense]—haven’t been pursuing appropriate methods to counter EA [electronic attack] for years,” a senior Air Force official with extensive experience on the F-22 told The Daily Beast. “So, while we are stealthy, we will have a hard time working our way through the EA to target [an enemy aircraft such as a Russian-built Sukhoi] Su-35s and our missiles will have a hard time killing them.”
The home-on-jam (HOJ) feature of the AIM-120B/C/D kicks in when the missiles’s receiver detects signals which didn’t come from it’s transmitter, and homes-in on the source transmitting them.
When in the home-on-jam mode the seeker interlaces the active pulses of the radar with passive guidance from the HOJ equipment.
DRFM isn’t new but the type used in the KNIRTI is more advanced; the DRFM digitizes the received signal and stores a coherent copy in digital memory. As needed, the signal is replicated and re-transmitted. Being a coherent representation of the original signal, the transmitting radar will not be able to distinguish it from other legitimate signals it receives and processes as targets. As the signal is stored in memory, it can be used to create false range targets both behind (reactive jamming) and ahead of (predictive jamming) the target intended for protection. The KNIRTI goes a step further by generating signals that indicate a false distance and location for the passive guidance on the HOJ.
Spot jamming occurs when a jammer focuses all of its power on a single frequency. While this would severely degrade the ability to track on the jammed frequency, a frequency-agile radar would hardly be affected because the jammer can only jam one frequency at a time. However the AIM-120D can only operate in X-band frequency range.
A frequency agile AESA radar can manage an intermittent lock on a target, depending on how quickly it can change frequency and re-establish lock on at a different frequency. This will degrade guidance of semi active radar homing missiles.
However an ARH missile with home-on-jam should be able to home-in on it easily.
The KNIRTI L175M jammer is an effective ECM against the most advanced AESA radars, to say that it can easily jam the radar seeker head of the outdated AMRAAM is an understatement.
KNIRTI SAP-518 wingtip jamming pod
KNIRTI SAP-14, intended for center line carriage on a large pylon.
https://www.quora.com/Is-it-true-th...ing-an-F-35’s-BVR-capabilities-less-effective
Active Radar Homing (ARH) missiles have a radar transceiver which is a device comprising both a transmitter and a receiver. The transceiver on ARH missile has a much shorter range relative to an aircraft’s on board radar and when it comes within range, it locks on to the target or goes active. Until it does, the missile is guided by launch aircraft’s radar.
The Raytheon AIM-120D also referred to as AMRAAM is one of the first of it’s kind to be developed and isn’t terribly advanced when compared to today’s state of the art ARH missiles. It weighs 152kg and measures 3.7m. Radar resolution is based on the size of the antenna. I don’t know the specific size of it’s antenna but apparently it’s smaller than other ARH missiles like the MICA, Meteor and R-77.
The guidance section features an active X-band radar terminal seeker using a solid-state transmitter with a low-side lobe, wide-gimbal antenna, and a built-in radio-frequency processor. The only wavelengths the AMRAAM operates in is X-band frequency range of 8–10 GHz which is easy to jam by the DRFM capable Sorbitsya and the new KNIRTI jamming pods carried by Flanker variants.
The KNIRTI L175M Khibiny M jamming system uses multiple techniques including DRFM and spot-jamming, which the AMRAAM is particularly susceptible to.
DRFM (digital radio frequency memory) jamming, or Repeater jamming is a repeater technique that manipulates received radar energy and re-transmits it to change the return the radar sees. This technique can change the range the radar detects by changing the delay in transmission of pulses, the velocity the radar detects by changing the doppler shift of the transmitted signal, or the angle to the plane by using AM techniques to transmit into the side lobes of the radar.
“Even with six AIM-120's in the F-22, sometimes it is not enough,” one senior Air Force pilot told the National Interest. “The Pk [probability of kill] of those missiles is low against a DRFM jamming fourth gen+ threat.”
“We—the U.S. [Department of Defense]—haven’t been pursuing appropriate methods to counter EA [electronic attack] for years,” a senior Air Force official with extensive experience on the F-22 told The Daily Beast. “So, while we are stealthy, we will have a hard time working our way through the EA to target [an enemy aircraft such as a Russian-built Sukhoi] Su-35s and our missiles will have a hard time killing them.”
The home-on-jam (HOJ) feature of the AIM-120B/C/D kicks in when the missiles’s receiver detects signals which didn’t come from it’s transmitter, and homes-in on the source transmitting them.
When in the home-on-jam mode the seeker interlaces the active pulses of the radar with passive guidance from the HOJ equipment.
DRFM isn’t new but the type used in the KNIRTI is more advanced; the DRFM digitizes the received signal and stores a coherent copy in digital memory. As needed, the signal is replicated and re-transmitted. Being a coherent representation of the original signal, the transmitting radar will not be able to distinguish it from other legitimate signals it receives and processes as targets. As the signal is stored in memory, it can be used to create false range targets both behind (reactive jamming) and ahead of (predictive jamming) the target intended for protection. The KNIRTI goes a step further by generating signals that indicate a false distance and location for the passive guidance on the HOJ.
Spot jamming occurs when a jammer focuses all of its power on a single frequency. While this would severely degrade the ability to track on the jammed frequency, a frequency-agile radar would hardly be affected because the jammer can only jam one frequency at a time. However the AIM-120D can only operate in X-band frequency range.
A frequency agile AESA radar can manage an intermittent lock on a target, depending on how quickly it can change frequency and re-establish lock on at a different frequency. This will degrade guidance of semi active radar homing missiles.
However an ARH missile with home-on-jam should be able to home-in on it easily.
The KNIRTI L175M jammer is an effective ECM against the most advanced AESA radars, to say that it can easily jam the radar seeker head of the outdated AMRAAM is an understatement.
KNIRTI SAP-518 wingtip jamming pod
KNIRTI SAP-14, intended for center line carriage on a large pylon.
https://www.quora.com/Is-it-true-th...ing-an-F-35’s-BVR-capabilities-less-effective
