
Not sure where to put this thread. I plunked it here because it has more to do with the VLO design and construction of the F-35, and also to the F-22 for that matter, than vs XYZ (other aircraft) or tactics.
Question: To what extent can massive computational number crunching be applied to VHF / UHF radars to develop weapons quality tracks of the F-35 or other VLO aircraft?
Submitted for consideration: comments & reporting regarding the Lockheed Martin APY-9 radar on the NG E-4D Advanced Hawkeye.
While I tend to take anything Majumbles says with a huge grain of salt, this story and others I have found suggests that sophisticated filters and time-motion analysis of UHF radar returns may enable the E-4D's APY-9 radar to detect and track Chinese and Russian VLO tactical aircraft, and by extension, possibly F-35 and F-22 as well. Of course, even if true, this simply means that all other 4th gen and earlier aircraft will be all that more naked in the electromagnetic spectrum as well.
The article by Westra is attached to this post as a PDF.
I know we have discussed the fact that VHF can detect stealth aircraft, but the consensus has been they cannot develop a weapons quality target track. This "space/time adaptive processing" mentioned suggests that Lockheed Martin (unclear of Northrop Grumman's role) has developed algorithms that, when applied to the data from the AESA radar, can develop these tracks.
Does this make sense?
What is to prevent the Russians from applying the same techniques to S300, S400, Sx00 IADS? I am assuming here that these IADS already use VHF or UHF radars. (Or has this all been discussed elsewhere and I've simply missed it? Although my searches for "APY-9" and "counterstealth" came back empty. Some discussion of Advanced Hawkeye, but from a netcentric point of view.)
Question: To what extent can massive computational number crunching be applied to VHF / UHF radars to develop weapons quality tracks of the F-35 or other VLO aircraft?
Submitted for consideration: comments & reporting regarding the Lockheed Martin APY-9 radar on the NG E-4D Advanced Hawkeye.
While I tend to take anything Majumbles says with a huge grain of salt, this story and others I have found suggests that sophisticated filters and time-motion analysis of UHF radar returns may enable the E-4D's APY-9 radar to detect and track Chinese and Russian VLO tactical aircraft, and by extension, possibly F-35 and F-22 as well. Of course, even if true, this simply means that all other 4th gen and earlier aircraft will be all that more naked in the electromagnetic spectrum as well.
The U.S. Navy’s Secret Counter-Stealth Weapon Could Be Hiding in Plain Sight
By: Dave Majumdar June 9, 2014
The Northrop Grumman E-2D Advanced Hawkeye maybe the U.S. Navy’s secret weapon against the emerging threat of enemy fifth-generation stealth fighters and cruise missiles.
The key to that capability is the aircraft’s powerful UHF-band hybrid mechanical/electronically-scanned AN/APY-9 radar built by Lockheed Martin. Both friend and foe alike have touted UHF radars as an effective countermeasure to stealth technology.
One example of that is a paper prepared by Arend Westra that appeared in the National Defense University’s Joint Forces Quarterly academic journal in the 4th quarter issue of 2009.
“It is the physics of longer wavelength and resonance that enables VHF and UHF radar to detect stealth aircraft,” Westra wrote in his article titled Radar vs. Stealth.
UHF-band radars operate at frequencies between 300MHz and 1GHz, which results in wavelengths that are between 10 centimeters and one meter long.
Typically, due to the physical characteristics of fighter-sized stealth aircraft, they must be optimized to defeat higher frequencies in the Ka, Ku, X, C and parts of the S-bands.
There is a resonance effect that occurs when a feature on an aircraft—such as a tail-fin tip— is less than eight times the size of a particular frequency wavelength. That omni-directional resonance effect produces a “step change” in an aircraft’s radar cross-section.
Effectively what that means is that small stealth aircraft that do not have the size or weight allowances for two feet or more of radar absorbent material coatings on every surface are forced to make trades as to which frequency bands they are optimized for.
That would include aircraft like the Chengdu J-20, Shenyang J-31, Sukhoi PAK-FA and indeed the United States’ own Lockheed Martin F-22 Raptor and tri-service F-35 Joint Strike Fighter.
Only very large stealth aircraft without protruding empennage surfaces — like the Northrop Grumman B-2 Spirit or the forthcoming Long Range Strike-Bomber — can meet the requirement for geometrical optics regime scattering.
“You can’t be everywhere at once on a fighter-sized aircraft,” one source told USNI News earlier in the year.
However, as Westra and many other sources point out, UHF and VHF-band radars have historically had some major drawbacks. “Poor resolution in angle and range, however, has historically prevented these radars from providing accurate targeting and fire control,” Westra wrote.
Northrop Grumman and Lockheed Martin appear to have overcome the traditional limitations of UHF-band radars in the APY-9 by applying a combination of advanced electronic scanning capability together with enormous digital computing power in the form of space/time adaptive processing.
The Navy would not directly address the issue, but service officials did say the APY-9 provides a massive increase in performance over the E-2C Hawkeye 2000’s radar.
“The E-2D APY-9 radar provides a significantly enhanced airborne early warning and situational awareness capability against all air targets including threat aircraft and cruise missiles,” said Naval Air Systems Command spokesman Rob Koon in an emailed statement to USNI News.
“The modern technology of the APY-9 radar provides a substantial improvement in performance over the E-2C’s APS-145 radar whose heritage dates back to the 1970s.”
[ blah blah blah ]
https://news.usni.org/2014/06/09/u-s-navys-secret-counter-stealth-weapon-hiding-plain-sight
The article by Westra is attached to this post as a PDF.
I know we have discussed the fact that VHF can detect stealth aircraft, but the consensus has been they cannot develop a weapons quality target track. This "space/time adaptive processing" mentioned suggests that Lockheed Martin (unclear of Northrop Grumman's role) has developed algorithms that, when applied to the data from the AESA radar, can develop these tracks.
Does this make sense?
What is to prevent the Russians from applying the same techniques to S300, S400, Sx00 IADS? I am assuming here that these IADS already use VHF or UHF radars. (Or has this all been discussed elsewhere and I've simply missed it? Although my searches for "APY-9" and "counterstealth" came back empty. Some discussion of Advanced Hawkeye, but from a netcentric point of view.)
- Attachments
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Radar versus Stealth (Arend Westra 2009).pdf
- File was found here: https://pdfs.semanticscholar.org/f127/d34dc8812b8e36b8ebea7763236e03286772.pdf
- (852.49 KiB) Downloaded 951 times
Take an F-16, stir in A-7, dollop of F-117, gob of F-22, dash of F/A-18, sprinkle with AV-8B, stir well + bake. Whaddya get? F-35.