#3737592 - 02/18/13 07:35 PM
Electronic Warfare-6
[Re: Hpasp]
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Hpasp
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Still in 1965...
The above mentioned smaller Self Protection Jammers (QRC-160-1, and the AN/ALQ-51) were working on the E band, they were capable of countering the SA-75MK Dvina (SA2A/B/F), and the SON4, SON9 AAA radars.
Stand Off Jamming further complicated the air picture, but it required bigger carrier due to its power and size requirement, that was flying outside of the SAM firing zone.
The ALT-6B used the Spot Noise Jamming technique, in the E band to counter the above mentioned threats. It had hydraulically tuned magnetron to aim its frequency during flight against a specific SAM site. This technique allowed narrower bandwidth, and greater jamming range. Limitations were, that against one Dvina fire control radar, you needed to aim exactly two ALT-6B (epsilon/azimuth), and provided protection only if the attacker plane was between the jammer and the site.
TAC used the EB-66E aircraft that carried 34pcs.
Last edited by Hpasp; 02/18/13 08:25 PM.
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#3737609 - 02/18/13 07:56 PM
Re: Electronic Warfare (EW), including Electronic Attack (EA) & Electronic Protection (EP)
[Re: Mdore]
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Hpasp
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Noise jammers don't transmit pulses, they transmit a continuous signal. There's no pulses you can filter.
A jammer that transmits a pulse based on the radar pulse is a deception jammer. It's used to create a false target. You already know this. That is Range Deception Jamming, or RGPO (Range Gate Pull Off). To successfully implement it, you will need to wait till the '70s, jammers with more intelligence. (ALQ-126, and the ALQ-131) This technique needs to predict when the next pulse will arrive, to be able to create false targets before and after the real one. We will discuss these, when we arrive there... If the jammer emits pulses when the radar pulse hits it, and then slowly introduces a time delay pulse by pulse, it'll look like the target split in two. The real aircraft in front, and the fake jammer target behind. That is the Range Deception Jamming, or RGPO (Range Gate Pull Off).If the radar uses a fixed PRF, then the jammer will know when the next pulse will arrive before it arrives, and so can transmit a jamming pulse before the radar pulse arrives. This also makes the target seem like it's split in two, but this time the closest target is the fake.
A radar can use jittering, where it varies it's PRF slightly pulse to pulse. This means the jammer will never know exactly when the next radar pulse will arrive, so can only produce fake targets behind the jammer, by starting a timer based on when the pulse arrives. Even the Dvina use basic jittering only cheap AAA radars use constant PRF.
Last edited by Hpasp; 02/18/13 07:59 PM.
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#3737627 - 02/18/13 08:29 PM
Electronic Warfare-7
[Re: Hpasp]
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Next year 1966, an improved QRC-160-1 pod was fielded in Vietnam.
The QRC-160-1A (QRC means Quick Reaction Capability) introduced the Modulated Noise Jamming technique against the SA-75MK Dvina (SA-2B/F) fire control radar.
Keeping the QRC-160-1 D/E band 4pcs Voltage Tuned Magnetron's (providing 100W FMCW jamming per magnetron), this pod introduced AM noise on the 6th~8th (96~128Hz) harmonic of the Dvina fire control radar's scanning frequency (16Hz).
At the Dvina scope, this technique resulted 6~8 vertical noise strobe, per plane. In case of a 4 ship formation, 24~32 vertical noise strobe could completely confuse, or blink the operators... ... causing longer target acquisition, and giving the Weasels more opportunities.
Last edited by Hpasp; 02/18/13 08:36 PM.
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#3740523 - 02/23/13 06:57 PM
Electronic Warfare-8
[Re: Hpasp]
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So far the Electronic Warfare made life more "interesting" for the SAM operators, but with experience and luck, they were still able to achieve... ... but it changed during the next year of the Vietnamese war, 1967. US EW agencies found out the frequency of the SA-75MK Dvina (SA-2B/F) missile beacon, and it turned out to be in a narrow 20MHz range. TAC immediately started to send planes with two QRC-160-1/1A pods, where one pod was solely dedicated for the missile beacon noise jamming. For several months, all missiles were lost right after launch.A new rule was enforced that before launch, the missile beacon channel should be checked for jamming. If jamming was present, it was forbidden to launch. As the situation become critical, Soviet experts were called in to find out and test the solution. During 1969, Technical Bulletin-1 was released to all Soviet allies using the SA-75MK Dvina system. It introduced several modifications: - Adding the H<1 switch by modifying the missile guidance electronic, reducing the minimum effective altitude into 500m. - Adding the RAB.po.K3 switch, in case of radio proxy fuse jamming. (this was feared by the Soviets, but never happened) - Adding the PA-00 cabin "doghouse" at the top of the RSNA cabin for visual target tracking, in dense jamming environment. - Adding the APP-75M instrument, to make launch calculations automatic. - V-750VK missile FR-I5AK beacon output was increased from 20W into 80W. After this bulletin was implemented, the beacon jamming become ineffective, and TAC stopped using it. Quite interesting, that SAC never received hint of this modification, so the B-52 bombers were still trying to jam the missile beacon in 1972, using up valuable jammers for nothing. Still in the same year (1967), the QRC-160 become official. QRC-160-1/1A E band Barrage Noise Jamming pod become the AN/ALQ-71, capable of jamming the S-25 Berkut (SA-1), SA-75MK Dvina (SA-2A/B/F), and the SON4, SON9 AAA systems. QRC-160-2 I band Barrage Noise Jamming pod become the AN/ALQ-72, capable of jamming the S-125 Neva (SA-3) system. This pod was sent into the Vietnam War, but was never flown operationally proving that the S-125 Neva (SA-3) was never used by the Nort Vietnamese during the war. QRC-160-8 D..G band Barrage Noise Jamming pod become the AN/ALQ-87, capable of jamming the S-75 Desna (SA-2C), S-75M Volhov (SA-2E) beside the systems already covered by the AN/ALQ-71. The NAVY also prepared to face new Soviet SAM equipment in Vietnam, by fielding the AN/ALQ-49 G/H band Angle Deception Jamming System, against the expected S-75 Desna (SA-2C) and the S-75M Volhov (SA-2E) system. It complemented the already fielded AN/ALQ-51.
Last edited by Hpasp; 02/23/13 08:30 PM.
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#3751033 - 03/14/13 08:35 PM
Re: Electronic Warfare-8
[Re: Mdore]
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piston79
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How do you defeat a target that is using modulated noise jamming? I think it depends of the SAM type... Your questions is too general...
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#3752154 - 03/16/13 08:01 PM
Re: Electronic Warfare-8
[Re: Mdore]
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Hpasp
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How do you defeat a target that is using modulated noise jamming? Considering the SA-75M Dvina (SA-2B/F) and the S-75M Volhov (SA-2E), the answer is simple against one plane using Modulated Noise Jamming ... ... you simply need to aim at the middle band. In case of two or three planes per formation, the picture could be extremely confused, with 2~3x6 vertical bands.
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#3752162 - 03/16/13 08:25 PM
Electronic Warfare-9
[Re: Hpasp]
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Hpasp
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In 1970, the AN/ALQ-101 pod was created to counter both the 10cm wave-lenght SA-75M Dvina (SA-2B/F), and the 6cm wave-lenght S-75M Volhov (SA-2E) systems. (one pod against several threats) The Volhov was expected by the US to pop up in Vietnam. (it never happened) This pod used TWT (Traveling Wave Tube), capable to cover the 2.6 to 5.2GHz frequency range. When this system was installed inside of the F-105G Wild Weasel aircraft, it was called the AN/ALQ-105. During this time, the US NAVY merged the... - AN/ALQ-49 G/H band (against the S-75M Volhov) - AN/ALQ-51A D..F band (against the SA-75M Dvina) ... systems into the AN/ALQ-100 angle deception system, available for the (A7A, F4J) planes. ...and the next technological barrier (called RANRAP) was soon to be fallen. *modified
Last edited by Hpasp; 03/17/13 09:08 AM.
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#3752311 - 03/17/13 06:50 AM
Re: Electronic Warfare-9
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Mdore
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How do you defeat a target that is using modulated noise jamming? Considering the SA-75M Dvina (SA-2B/F) and the S-75M Volhov (SA-2E), the answer is simple against one plane using Modulated Noise Jamming ... ... you simply need to aim at the middle band. But, unless the modulation of the jamming is exactly synced with the horizontal scanning frequency, the middle band could be slightly to the side of where the actual target is? Wouldn't that work as crude angle-jamming? Making the missile likely to miss?
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#3752320 - 03/17/13 07:38 AM
Re: Electronic Warfare-9
[Re: Mdore]
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piston79
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What the manual says (Google translation): Work under the influence of noise on SNR modulated continuous interference, leading away the corners If the primary and secondary continuous band of noise narrowed or expanded, creating the illusion of displacement director of the angular coordinate, this is evidence of the use of noise-modulated continuous enemy interference. The procedure for finding the jammer, frequency hopping channels sighting targets and attack targets in this case is the same as when shooting against continuous unmodulated noise jamming. The main features of combat operation in conditions of the considered noise associated with the choice of method of tracking and techniques to support the direction on the angular coordinates. Tracking the jammer is only in RS with with system of averaging the target signal off, as modulation noise voltage with a frequency which is a multiple scanning frequency SNR leads to oscillations (lead) energy ¬ cal center interference signal from the angular coordinates ca ¬ simplicity beats, which dramatically increases the error automatically with ¬ spending. Inclusion scheme smoothing (averaging noise) limits the observed signal from the bottom and can not determine the true center of the band noise. At the beginning of the tracking must support operators to define target motion on the screen at maximum brightness and width * interference, in order to be able to distinguish false - the offset signal interference caused by the asymmetric change the brightness and the bandwidth of the displacement caused by the moving . The operator remembers the position of the middle band interference to its maximum size and brightness in the future continues to monitor the selected point of support. Especially complex work of operators with a large beat frequency modulation frequency and frequency scanning. In these cases, the screen shows frequent narrowing lanes, creating the illusion of flashing, resulting in a rapid visual attrition and weakening of the operator's attention. These influences can be lowered by reducing the brightness and increased by RRU by changing bandwidth interference. If noise modulated jamming was created by the type of inversion (constant-SVR, th), the support is in the middle of the band, regardless of 1eravnomernoy brightness.
Last edited by piston79; 03/17/13 07:56 AM.
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#3752343 - 03/17/13 09:49 AM
Electronic Warfare-10
[Re: Wolfhound]
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Hpasp
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The next breakthrough in the field of Electronic Warfare was the Westinghouse AN/ALQ-131 pod, fielded by the USAF. This was the first jamming pod, using re-programmable software with digital processor called VHSIC (Very High Speed Integrated Circuit) that time, running on 1MHz. The software of the pod, was able to track and predict the PRF of the threat, a capability was called RANRAP (Random Range Program). The False Target Jamming technique created 7~8 realistic targets, that had different sizes and some of those were placed closer/further than the jamming plane. Similar capability was introduced by the NAVY with the Sanders AN/ALQ-126 system built into the F-4, F-14, F-18, A-4, A-6, and A-7 planes.
Last edited by Hpasp; 03/17/13 09:50 AM.
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#3752362 - 03/17/13 10:53 AM
Re: Electronic Warfare-10
[Re: farokh]
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piston79
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[b]guys... pleas e guide me about DM jammer... do u have any picture of it? List of jammers mounted on B-52/EB-66 (during Vietnam war): Google them and pick-up some pictures...
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#3752365 - 03/17/13 11:03 AM
Re: Electronic Warfare-10
[Re: farokh]
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Hpasp
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guys... pleas e guide me about DM jammer... do u have any picture of it? and someone tell me this pod could be arm on what kind of aircraft? DM jammer, what is that? These techniques are on the table, and we already discussed the red colored ones: Denial Jamming: - Barrage Noise Jamming- Spot Noise Jamming- Swept Spot Noise Jamming - Cover Pulse Noise Jamming - Modulated Noise Jamming Deceptive Jamming: - False Target Jamming- Range Deception Jamming (Range Gate Pull Off) - Angle Deception Jamming ( Inverse Amplitude Modulation, Inverse Gain Jamming, Swept Square Wave) - Velocity Deception Jamming (Velocity Gate Pull Off, Doppler Noise, Narrow-band Doppler Noise, Doppler False Targets) - Mono-pulse Deception Jamming (Cross Polarization Jamming, Cross Eye Jamming)
Last edited by Hpasp; 03/17/13 11:07 AM.
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#3752378 - 03/17/13 11:42 AM
Re: Electronic Warfare-10
[Re: Hpasp]
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farokh
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I-RAN
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guys... pleas e guide me about DM jammer... do u have any picture of it? and someone tell me this pod could be arm on what kind of aircraft? DM jammer, what is that? These techniques are on the table, and we already discussed the red colored ones: Denial Jamming: - Barrage Noise Jamming- Spot Noise Jamming- Swept Spot Noise Jamming - Cover Pulse Noise Jamming - Modulated Noise Jamming Deceptive Jamming: - False Target Jamming- Range Deception Jamming (Range Gate Pull Off) - Angle Deception Jamming ( Inverse Amplitude Modulation, Inverse Gain Jamming, Swept Square Wave) - Velocity Deception Jamming (Velocity Gate Pull Off, Doppler Noise, Narrow-band Doppler Noise, Doppler False Targets) - Mono-pulse Deception Jamming (Cross Polarization Jamming, Cross Eye Jamming) i see DM jammer on this page ... ASHULUK ... ! also i see this type of jammer in allied forces and vietnam also libya ... what plane can use it ?
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#3754222 - 03/20/13 06:05 PM
Electronic Warfare-11
[Re: Hpasp]
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Hpasp
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On the 6th of October, 1973 the Yom Kippur War was started. First time in History, a Continuous Wave illuminated, Semi Active guided Surface to Air Missile system was deployed. This system use the SURN (Straight Flush*) radar to illuminate the target with a CW signal, while the missile would track the received echo from the target... ... most of the jamming techniques available at that time, would simply highlight the jamming target for the missile SARH head, making the actual guidance more precise. Israel started the war with AN/ALQ-101 pods, and received further 40pcs of AN/ALQ-119 as an US aid. The AN/ALQ-119 had the extended capability of jamming the Neva (SA-3) complexes, beside the Dvina (SA-2B/F) and the Volhov (SA-2E) systems that was already covered by the AN/ALQ-101. During the war, these systems were solely used to jam the Dvina/Volhov/Neva (SA-2B/C/E/F, SA-3B) systems. The jamming of the KUB (SA-6) was not attempted, in a fear of attracting the SA-6 missiles. * Straight Flush means 5 cards in poker, relating to the 5 frequency, the SURN uses during engagement
Last edited by Hpasp; 03/20/13 06:29 PM.
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Exodus
by RedOneAlpha. 04/18/24 05:46 PM
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