Iran successfully used Russian-made radar to track US F-35 jets — designer

[ACE OF HEARTS]

In lay man terms, it's easy to detect a stealth / LO aircraft BUT it is totally a different thing to get a Weapons Grade Radar Lock on the aircraft and bring it down.

Just detecting an aircraft won't win you any battles no matter how many SAMs you fire at it.

 

[PakFactor]

Am going to clarify that...

These are the main target resolutions...

- Altitude
- Airspeed
- Heading
- Range
- Aspect angle

The foundation of those resolutions is the pulse. To generate a pulse, you apply power then you cut off power. Like this...

Each pulse have a leading edge (LE) and a trailing edge (TE). Each pulse that reflects off a body produces a return pulse which also have an LE and a TE. The radar then uses the LEs and TEs to calculate the above five target resolutions.

If you send out 100 pulses and you receive 75 return pulses, some consecutively and some scattered, you would still have a target as defined by the radar.

But what the 'stealth' aircraft does is instead of giving you 75 pulses, you get something like 5 return pulses and not consecutive. In other words, because those five pulses are scattered throughout the pulse train, the radar will classify those five pulses as background noise.

Is there such a thing as a 'pulse train' or is it a made up phrase?

https://dspace.mit.edu/handle/1721.1/41030

In this study a linear frequency modulated chirp signal is approximated using two stepped-frequency pulse train waveforms, a continuous wave pulse train and a linear frequency modulated pulse train.​

​

A pulse train can contain one pulse or one million pulses, depending on the system's sophistication. But there is a negative side to having one million pulses in a single burst. Each pulse can be seen as a packet of energy because of the LE and TE. Energy on/off. The shorter the pulse, the less energy. The lower the energy, the lower the distance the pulse can travel without signal loss.

So when you get less than %.001 of your pulse train, the target is essentially 'invisible'. Not because the 'stealth' aircraft does not reflects but because the reflections are extremely sporadic and scattered.

As the 'stealth' aircraft gets closer and closer, more and more packets of energy hits the 'stealth' aircraft and the reflected pulses would begin to cluster, in other words, more and more reflected pulses would appear consecutively. A sequence of anything is a pattern and in radar detection, patterns are good. For the 'stealth' aircraft, patterns are not good.

So when we see claims like these in the public domain, those who understand radar detection principles, design, and operations, usually roll their eyes. Like this --

By the time you get the patterns consecutively the stealth fighter is gone after releasing the payload.

 

[TheImmortal]

By the time you get the patterns consecutively the stealth fighter is gone after releasing the payload.

All conjecture. Only Russia, Iran, and China know how well their algorithms can interpret radar data.

In case of Russia/China they can use reinforcement learning AI programs. By using their own 5th gen aircraft constantly to test their own air defense network, they can aid in improving signal and data packet analysis.

A theory I have for a next gen Radar would be to set up points throughout a subject country connected to a supercomputer mainframe vis a vi “the cloud”. Each Radar would shoot radar waves across the country covering the entire country in radar waves.

Assuming an F-35 or LO object renters the airspace even if it scatters the signal, the signal will be picked up by the array of radars fed into the supercomputer that will “piece” together the signals based on pattern analysis on artificial intelligence (ML, Reinforcment learning, etc).

In this instance, the radars would merely be feeding any received data to the supercomputer to build a picture of what is flying in the airspace at any given time.

Again not sure the feasibility of such an endeavor with today’s technology, but it would solve the detection problem. It wouldn’t solve the problem of early warning (outside the borders) problem as there would be no waypoints outside of the country, but it would eliminate blindspots inside the country.

 

[PeeD]

My point was user is saying brute force technique does not work on F-35 at LR. He seems to think energy can be sufficiently dissipated at the longer ranges.

Well what users here think is unimportant in terms of quantitative analysis: He don't know about Rezonans performance, nor about F-35 LO performance.

At what point energy levels will be too low for detection and track depends on the LO means and level of it applied. Alone with RAM/RAS out of the game, things like very dire, but even confronted with a extrem high power array --> defeat.

Note that there is no problem to filter out the F-35: Doppler processing can't be notched forever, it will soon recognize that the target must be a jet, a LO jet.

 

[gambit]

Being low radar observable, aka 'stealth', DOES NOT give the pilot a license to be careless.

Historically, by the time you -- the pilot -- found you are being scanned, most likely the seeking radar marked you. The F-117, and subsequent 'stealth' aircrafts, upset that balance.

Being low radar observable, aka 'stealth', allows you the advantage of knowing that you are being scanned WITHOUT the seeking radar knowing that it has scanned you. This applies even to long wavelengths system that tries to exploit resonance in the Rayleigh region. It is called combat tactics. Look it up.

Why do people get the idea that the F-22 pilot will just continue on his merry way when his RWR started beeping?

The laws of physics plus combat tactics make a lethal threat. For the B-2 pilot, when his RWR alerted him that he is at the edge of the enemy's radar net, he will make adjustments in his physical profile to present the lowest possible EM cross section as he alters course to avoid the radar's highest signal strength. The US have been flying 'stealth' for decades while the best of the rest still struggles in the labs. You think we would have figure out how to defeat long wavelengths by now?

 

[PeeD]

You think we would have figure out how to defeat long wavelengths by now?

No, for people knowing about the physics involved, won't think.

Its like saying by 2200 speed of light certainly wont be the limit because people worked 180 years to overcome it.
Or AIM-120 doubles its max. range with the same motor diameter and length from 50km to 160km in its recent version by... breaking all physical rules.
Its not F-16.net here.

RAM-RAS employ known physical effect for RF energy dissipation.
At least, even if we assume Russians were somehow retards: When Serbians gave them the F-117 remains they knew what physical mechanisms were used by U.S stealth platforms.

The same honeycomb RAS is still the solution used by F-22/35 and B-2. No groundbreaking inventions there. No black project technology leaps. No Area 51 secret mysteries.


Stealth is very useful if employed in right conditions: Being painted by Rezonans is not such a condition.

PS: If a stand-off Resonanz tries to track your stealth platform, just reduce altitude to defeat it via LOS constrain. Neither Rezonans nor the stealth aircraft are invincible.