How stealthy is your stealth aircraft?

[glad rag]

Some intriguing snippets in article below.

https://nationalinterest.org/blog/the-buzz/northrop-grummans-e-2d-advanced-hawkeye-the-us-navys-eyes-18794

example.

"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 omnidirectional 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......"

[GlosMikeP]

Radar stealth was a busted flush - proved so in the 1980s with bistatic radar.

See IEE publication 1993, Advanced Radar Techniques and Systems edited by Gaspare Galati, Chapter 11 by M R B Dunsmore of the Royal Signals and Radar Establishment, Malvern.

All that money pumped into pretending aircraft can be made invisible to radar....wasted. Good article here: Russian / PLA Low Band Surveillance Radar Systems (Counter Low Observable Technology Radars) (http://ausairpower.net/APA-Rus-Low-Band-Radars.html)

[Pontius Navigator]

Mike,he did say [which frequency bands they are optimized for......

We used to maximise our jamming effect by concentrating on a particular threat radar. By denying height, for instance, we could 'hide' in plain sight. Bring in an alternative threat and our cloak was nothing.

[GlosMikeP]

Mike,he did say

We used to maximise our jamming effect by concentrating on a particular threat radar. By denying height, for instance, we could 'hide' in plain sight. Bring in an alternative threat and our cloak was nothing.
With bistatic radar, it doesn't matter PN: the aircraft shaping, used to deflect return energy to monostatic radars, in fact helps detection. Then the RAM etc is irrelevant.

All that happens is the extra airframe and RAM weight impairs ac performance whilst adding nothing meaningful to invisibility - regardless of RF band. The E-2D UHF radar is an additional, powerful further counter to stealth, as was noted during the post Nimrod AEW3 competition that brought the E-3D into service, and a pretty good option if bistatic capability isn't available.

The strength of bistatics is that there are no external signs on antennas etc to indicate it's available, which is of itself a stealthy (downright sneaky) capability. The stealth ac might know where the illuminator is but has no way of knowing where the receiver is, nor any way to counter detection: jamming the illuminator doesn't make any difference to detection.

[KenV]

With bistatic radar, it doesn't matter PN: the aircraft shaping, used to deflect return energy to monostatic radars, in fact helps detection. Then the RAM etc is irrelevant..Detecting the presence of a stealth aircraft and knowing the range to the aircraft and it's altitude are two very different things. And having sufficient precision tracking data for a missile fire solution and guidance is yet another thing.

[GlosMikeP]

Detecting the presence of a stealth aircraft and knowing the range to the aircraft and it's altitude are two very different things. And having sufficient precision tracking data for a missile fire solution and guidance is yet another thing.
No it isn't. Read M R B Dunsmore's section in the IEE document and all will be revealed. No need to get absorbed in the hard sums; the implications stand out pretty well.

[KenV]

No it isn't. Read M R B Dunsmore's section in the IEE document and all will be revealed. No need to get absorbed in the hard sums; the implications stand out pretty well.Already read it. Bistatic radars can make range estimates, but cannot make precision range measurements. And they cannot make altitude measurements at all. So while bistatic radars may generate enough data to guide an aircraft to the vicinity of a target, the pilot must do the final targeting visually. Bistatic radars cannot generate enough data to provide a fire solution for a missile, much less actively guide the missile to the target. However, a bistatic radar CAN provide enough data to detect and localize a target sufficiently to provide cuing for a conventional radar to put enough energy into a volume of space to detect and track a stealth aircraft. But this basically limits the conventional radar to tracking one target at a time.

[GlosMikeP]

You're thinking terrestrial surveillance radars only, I reckon. Even so, the produced picture is good.

It's feasible to do airborne bistatics (or indeed, multi-static) and isn't limited to L and S bands. That was proposed in the 80s, too. It is possible to get height, though the processing demand is very high. My last words; for more you'd need access to the original reports.

[JG54]

No it isn't. Read M R B Dunsmore's section in the IEE document and all will be revealed. No need to get absorbed in the hard sums; the implications stand out pretty well.


I'd imagine there's every need to become 'absorbed in the hard sums' to back up any guff on Carlo Kopp's site - particularly guff which cites thirty year old studies / papers not widely disseminated elsewhere.

[GlosMikeP]

You'll need an engineer's slide rule if you do....I must hunt mine down.

[BEagle]

I wonder what success the UK's OTH radar would have had in detecting 'stealth' aircraft?

The relocatable over-the-horizon radar was to have included a transmitter site at St. David's airfield and a receiver site at Blakehill Farm disused airfield. It was cancelled in 1991 due to pressure on the defence budget during GW1 and the so-called post-Cold War 'peace dividend'.

Another wise decision....:hmm:

[PPRuNeUser0139]

Cobra Mist?

[GlosMikeP]

I wonder what success the UK's OTH radar would have had in detecting 'stealth' aircraft?

The relocatable over-the-horizon radar was to have included a transmitter site at St. David's airfield and a receiver site at Blakehill Farm disused airfield. It was cancelled in 1991 due to pressure on the defence budget during GW1 and the so-called post-Cold War 'peace dividend'.

Another wise decision....:hmm:
That was another result from an RSRE product from the 80s. Two radar types were trialled; one from a field in Welcombe, a bit south of Hartland Point; the other from a place near Dungeness B (no me neither!) in Essex. Both highly successful and with novel waveforms, more like X band than HF. The targets for the SW approaches were 100 Sqn Canberras and for the Essex end, a rented helicopter towing a Swerling 1, 1 sq m sphere at nigh on 10000ft.

We lost a lot in selling off RSRE, RAE etc. The trouble was the products were given away to industry for the likes of ICL, GEC, Plessey, Cossor et al to brand with their names. When the question came 'But what have the government research establishments produced?', the answer didn't look too good, but in fact had been a rich underpinning of UK defence (and civil) industries - and their shareholders. I wonder how many people know the liquid crystal display technology was invented at RSRE, as were voice activated systems, IR vision equipment, the first 'touch display (1960s).......the list goes on. Oh, and radar, both conventional and anti-stealth.