F-22 / F-35 5th Generation jets | News & Discussions.

[moon_light]

I gave the visible spectrum as an example so he could understand what I was talking about. The F-22 is not stealthy in the visible spectrum, so you can see the F-22 in many other parts of the spectrum and not just the X band, say at 100GHz

Dude , you can not make a jump comparison like that. Can we see a piece of plastic in visible spectrum ? yes , can we see it at 100 Ghz ? i dont think so
and how about attenuation problem ?

Yes, a searchlight, but a searchlight that doesn't work in the visible spectrum. This 'searchlight' that's coming up can do facial recognition from 400Km away and can even check what's inside the weapons bay of aircraft. It can even count the number of people inside an aircraft. Think of a TV camera instead, but with X ray vision, that's a much better example. It will have a resolution that's 20+ times higher than current AESA radars. But this will work in far lower frequencies, not the visible spectrum, maybe at least not yet.

Are you talking about the things in startrek ?

The F-22/35 were not made for VLO in the mmw bands. It does work a bit in the mmw, but not as much as cm bands. Radars in the mmw bands are coming up, with very high resolutions.

we already have them in Brimstone missiles and Long bow radar
what make you think MMW work better again VLO aircraft than X band ? practically speaking MMW lose like 80% of power through 1 km of atmosphere , i cant see how it could be better.

 

[randomradio]

If you read them then you will see that apart from the first one ( which is basically triangulation) the rest are not applicable for the aircraft vs aircraft situation

For aircraft, they use Time Difference of Arrival. It's a far more efficient method. And it gets more accurate with multilateration, that is more aircraft separated over large distances.

The point I was making was you can calculate range through passive techniques. No different from how astronomical distances are measured, even though the math used is different. So, it's all in the math.

What is mean is that the name " passive radar " creating the illusion that the radar can operate silently , in fact it still need a transmitter and still obey the rule of normal radar

Yes. Exactly. Except that the radar itself doesn't come with the transmitter. Or in most cases, the radar won't actively emit, like in the case of current fighter radars that work in passive mode. The only difference is a passive radar can be tuned to a larger assortment of frequencies.

Passive radars that are marketed are designed as radars, but without the transmitter.

 

[moon_light]

For aircraft, they use Time Difference of Arrival. It's a far more efficient method. And it gets more accurate with multilateration, that is more aircraft separated over large distances.

The point I was making was you can calculate range through passive techniques. No different from how astronomical distances are measured, even though the math used is different. So, it's all in the math.

The problem with time different arrival is that it required the same pulse to hit all these "aircraft separated over large distance" . which is not easy ,given new fighter radar have very high gain ( narrow beamwidth)
The point i was making is that passive range are effective again stationary ground target, not so much again moving aircraft.

Yes. Exactly. Except that the radar itself doesn't come with the transmitter. Or in most cases, the radar won't actively emit, like in the case of current fighter radars that work in passive mode. The only difference is a passive radar can be tuned to a larger assortment of frequencies.
Passive radars that are marketed are designed as radars, but without the transmitter.

You can work in your so-called " passive mode" but you still need a transmitter somewhere , so what exactly the point ?

 

[randomradio]

Dude , you can not make a jump comparison like that. Can we see a piece of plastic in visible spectrum ? yes , can we see it at 100 Ghz ? i dont think so

You can see pretty much everything using a radar.

and how about attenuation problem ?

The energy is still there. You need to make major changes in hardware to detect even the smallest amounts of energy, and that's happening now.

Are you talking about the things in startrek ?

What?

we already have them in Brimstone missiles and Long bow radar
what make you think MMW work better again VLO aircraft than X band ? practically speaking MMW lose like 80% of power through 1 km of atmosphere , i cant see how it could be better.

Stuff's changing really fast. If you want more information, you will just have to wait. The military makes the pioneering discoveries first in this field and all of that remains a secret for many years.

It is not just mmw alone, it's about what you do with the signals that you have received. F-22/F-35 aren't perfect stealth aircraft. They are not invisible. Basically, with the new hardware that's coming up, the F-22 will light up like a Christmas tree on this radar.

The problem with time different arrival is that it required the same pulse to hit all these "aircraft separated over large distance" . which is not easy ,given new fighter radar have very high gain ( narrow beamwidth)
The point i was making is that passive range are effective again stationary ground target, not so much again moving aircraft.

It's not such a big problem now. The range accuracy depends on how many aircraft you use, otherwise in some cases, the track generated is much more accurate than a radar. You can perform TDOA with a single aircraft also.

You can work in your so-called " passive mode" but you still need a transmitter somewhere , so what exactly the point ?

You didn't get it. Passive radar and passive modes are not the same. A passive radar can never go active.

The one advantage of a passive radar is, it is undetectable compared to an active radar.

 

[moon_light]

You can see pretty much everything using a radar.

The question is at what distance

The energy is still there. You need to make major changes in hardware to detect even the smallest amounts of energy, and that's happening now.

In that case why not just use X band ? what the point of going to higher frequency so that you will have less signal to receive ?

What?

The thing you described here

This 'searchlight' that's coming up can do facial recognition from 400Km away and can even check what's inside the weapons bay of aircraft. It can even count the number of people inside an aircraft

doesnt exist

It is not just mmw alone, it's about what you do with the signals that you have received. F-22/F-35 aren't perfect stealth aircraft. They are not invisible. Basically, with the new hardware that's coming up, the F-22 will light up like a Christmas tree on this radar.

That very vague , it would be like me saying , with the new RAM F-35/ F-22 will be invisible to everything

It's not such a big problem now. The range accuracy depends on how many aircraft you use, otherwise .

It is a problem and a really big one that is , the accuracy depending on how seperated your aircrafts from each others , if they are too close then the track quality will be bad , if theyr are too far then the radar beam wont hit them at the same time

in some cases, the track generated is much more accurate than a radar..

what kind of radar ? early warning ? could be . Fire control radar ? not possible

You can perform TDOA with a single aircraft also.

To generate firing solution by TDOA you need multiple aircrafts fly at long distance from each others

You didn't get it. Passive radar and passive modes are not the same. A passive radar can never go active.

The one advantage of a passive radar is, it is undetectable compared to an active radar.

Your passive radar is will be useless without the transmitter , so what the point if the receiver can not be detect if the transmitter itself can be detect ?

 

[gambit]

What make you think MMW is more effective again stealth aircraft than X-band ?

The millimeter wave range is not better against 'stealth'. People throws these initials and phrases out without knowing the basics.

We need to return to the basics.

The above is a simplified visual representation of a radar pulse train.

Each pulse have a PHYSICAL length. Each pulse have a start (leading edge) and an end (trailing edge) and because of this, each pulse can be seen as a package FINITE amount of energy.

The reason why the X-band, or centimetric region, is used because this package of energy offers the best target resolutions under most, not all, situations and environments. Those target resolutions are:

- Heading
- Speed
- Altitude
- Aspect angle

Moving away from the X-band region and any of those four resolutions begins to change in accuracy, and the changes are not always for the better.

Longer wavelengths contains more energy per pulse, thereby putting more energy on target, resulting in a stronger return. On the other hand, longer pulses means lower accuracy over time, affecting mostly target speed but the other three items are also negatively affected. Essentially, longer wavelengths means longer pulses equals lower resolutions that requires time.

So why is the mm wavelengths NOT effective against 'stealth' ? Simple: Too little energy.

Too little energy means the pulses cannot travels far. Too short a physical wavelength and the pulse will get absorbed by small barriers like raindrops.

https://en.wikipedia.org/wiki/Extremely_high_frequency

Compared to lower bands, radio waves in this band have high atmospheric attenuation; they are absorbed by the gases in the atmosphere. Therefore, they have a short range and can only be used for terrestrial communication over about a kilometer.

People are straining in their zeal to downplay the effectiveness of low radar observability. They eagerly grasp at any shallow news articles written by technically ignorant writers working to make deadlines.

Gambit as an expert , what do you think about these graphs ? :

Nothing unusual about them.

An aircraft is a complex body and as such, different radar positions, or viewing locations, will produce a different EM representation of the same body. We know this for decades.

 

[moon_light]

Nothing unusual about them.

An aircraft is a complex body and as such, different radar positions, or viewing locations, will produce a different EM representation of the same body. We know this for decades.

I understand that , what seem surprising for me is Mig-29 seem to have much lower RCS than F-16

moreover B-2 frontal RCS doesnt change that much between 1 Ghz and 10 Ghz

 

[randomradio]

The question is at what distance

The F-22 should easily be detected, tracked at ranges more than 300Km.

In that case why not just use X band ? what the point of going to higher frequency so that you will have less signal to receive ?

The F-22 is better shaped against X band, so why make the job more difficult? You can get more information from higher frequencies.

The thing you described here

doesnt exist

That's some of the capabilities of the new radar being made.

That very vague , it would be like me saying , with the new RAM F-35/ F-22 will be invisible to everything

Electronics use 'electrons'. That's obvious. In the future we are no longer going to use electrons, we are moving straight away to photons. In about 10 years, the electronics industry will make way for the photonics industry. There's a brand new major industry starting up.

This radar will be the first generation quantum radar. There I went and said it. So you will basically have to throw away about 60 or 70% of what you know about a conventional radar to talk about this radar.

Eventually this radar will work in the entire spectrum, not just bits and pieces of the spectrum. When you interact with photons directly, doing facial recognition from 400Km away is a piece of cake. There is no noise, so interference is practically zero, and any change in quantum state will give away the position of aircraft.

Basically, this radar will make current measures of stealth obsolete.

Classic mechanics will soon be an outdated concept. And soon means really soon. The Chinese have already launched the first quantum satellite.

 

[gambit]

Potayto, potahto. As long as you agree about the way it works, you can call it whatever you want. There are disagreements about what a system is called everywhere. Like the French don't believe in the marketing claims of the F-35's marketing team for what constitutes a 5th generation.

Their loss. But no matter, we will protect the French anyway.

A passive radar does not have a transmitter.

Then it cannot be called a 'radar'.

Actually I'm not. It's next generation in radar technology. One step ahead of the AESA. An ultra-wideband radar.

Yes, you are.

You asked for a radar that works in the 'visible spectrum'. Am willing to bet that the only thing you know of the 'visible spectrum' is how to spell the English words. The 'visible spectrum' is visible light. Simple as that.

I gave the visible spectrum as an example so he could understand what I was talking about. The F-22 is not stealthy in the visible spectrum, so you can see the F-22 in many other parts of the spectrum and not just the X band, say at 100GHz.

Aaahh...NOTHING is 'stealthy' in the visible spectrum. It is called a 'flashlight'.

Yes, a searchlight, but a searchlight that doesn't work in the visible spectrum.

Yes, that is called radar using the non-visible spectrum.

This 'searchlight' that's coming up can do facial recognition from 400Km away and can even check what's inside the weapons bay of aircraft. It can even count the number of people inside an aircraft. Think of a TV camera instead, but with X ray vision, that's a much better example. It will have a resolution that's 20+ times higher than current AESA radars. But this will work in far lower frequencies, not the visible spectrum, maybe at least not yet.

Then go check the science fiction section. Particularly 'Star Trek'. But do not waste bandwidth by debating something you have no interests in learning.

 

[moon_light]

The F-22 should easily be detected, tracked at ranges more than 300Km..

That based on what ??????????? did you just make up number as you go ?

The F-22 is better shaped against X band, so why make the job more difficult? You can get more information from higher frequencies..

No you cant ,given the lose in energy as Gambit said

That's some of the capabilities of the new radar being made.
Electronics use 'electrons'. That's obvious. In the future we are no longer going to use electrons, we are moving straight away to photons. In about 10 years, the electronics industry will make way for the photonics industry. There's a brand new major industry starting up.

This radar will be the first generation quantum radar. There I went and said it. So you will basically have to throw away about 60 or 70% of what you know about a conventional radar to talk about this radar.

Eventually this radar will work in the entire spectrum, not just bits and pieces of the spectrum. When you interact with photons directly, doing facial recognition from 400Km away is a piece of cake. There is no noise, so interference is practically zero, and any change in quantum state will give away the position of aircraft.

Basically, this radar will make current measures of stealth obsolete.

Classic mechanics will soon be an outdated concept. And soon means really soon. The Chinese have already launched the first quantum satellite.

Now iam convinced that you are trolling

 

[gambit]

I understand that , what seem surprising for me is Mig-29 seem to have much lower RCS than F-16

What you posted are simulated. There are limits to such simulations. But even if the simulations are precise and accurate enough, if the lower RCS does not give the MIG at least 1/2 detection range advantage over the F-16, that reduction is tactically useless. In other words, if the MIG can detect the F-16 at 100 km while the F-16 can detect the MIG at 80 km, that 20 km gap will be covered by the F-16 in one second flight time. Not enough for the MIG pilot to reposition himself.

 

[randomradio]

Too little energy means the pulses cannot travels far. Too short a physical wavelength and the pulse will get absorbed by small barriers like raindrops.

Forget basics of classic mechanics. I would suggest start studying quantum mechanics.

We are talking about Microwave radars, right from 1GHz to 100GHz and beyond.

Then go check the science fiction section. Particularly 'Star Trek'. But do not waste bandwidth by debating something you have no interests in learning.

http://www.news18.com/news/tech/chi...-quantum-communication-satellite-1281472.html

Science fiction is now reality.

Now iam convinced that you are trolling

It's not trolling. It's reality. Read up on quantum radars first.

Google china's first quantum satellite.

 

[gambit]

Forget basics of classic mechanics. I would suggest start studying quantum mechanics.

You are talking about something that is at least a couple decades out of the laboratory. You are getting to be like the PDF Chinese where just because it can be done in the lab, it will be done tomorrow.

Let me know when you are back to reality.

 

[moon_light]

Forget basics of classic mechanics. I would suggest start studying quantum mechanics.
We are talking about Microwave radars, right from 1GHz to 100GHz and beyond.
http://www.news18.com/news/tech/chi...-quantum-communication-satellite-1281472.html
Science fiction is now reality.
It's not trolling. It's reality. Read up on quantum radars first.
Google china's first quantum satellite.

No offense , i dont think you understand what you talking about at all

What you posted are simulated. There are limits to such simulations. But even if the simulations are precise and accurate enough, if the lower RCS does not give the MIG at least 1/2 detection range advantage over the F-16, that reduction is tactically useless. In other words, if the MIG can detect the F-16 at 100 km while the F-16 can detect the MIG at 80 km, that 20 km gap will be covered by the F-16 in one second flight time. Not enough for the MIG pilot to reposition himself.

According to the simulation Mig-29 frontal RCS is around 1 m2 while the value for F-16 is around 10 m2 that is 50% detection range as far as i know. Another point is : if both F-16 and Mig-29 was cruising at mach 1 , they will take 27 seconds to close the 20 km gap.
Btw how about jamming effectiveness as reduction of RCS ?

 

[gambit]

What is mean is that the name " passive radar " creating the illusion that the radar can operate silently , in fact it still need a transmitter and still obey the rule of normal radar

Illusion is correct.

Radar detection is a two-parts process: Transmission and Reception.

Without any part, the process cannot be called 'radar'.

The misleading part of 'passive' is that most people associate the transmission part to be of the same ownership. If you are the owner of the reception part, then you must the owner of the transmission part, no ?

That is not true. The original concept of radar said nothing about ownership. It just simply said that if there is a transmission, if that transmission bounced off a body, and if you receive that echo, you just have a basic radar detection process. It would be nice if you are the owner of both transmit and receive.

If we go by the misleading meaning of a 'passive radar', I could put such a system in the middle of the Sahara, then park the Goodyear blimp in front of it, and that radar would not see the blimp at all.

Now...If someone else point his transmitter at the blimp, and your receiver picked up the echo, now we have the full process, which mean there can be no such animal as a 'passive' radar.

The misleading part of the 'passive' radar is OWNERSHIP. This guy just do not understand it.

According to the simulation Mig-29 frontal RCS is around 1 m2 while the value for F-16 is around 10 m2 that is 50% detection range as far as i know. Another point is : if both F-16 and Mig-29 was cruising at mach 1 , they will take 27 seconds to close the 20 km gap.

Fully loaded ? I doubt that.

The reason we used a clean F-16 as the par for 'stealth' is because it is: Clean.

When you add this...

To the F-22, you destroyed any 'stealth' shaping the jet has.

A clean F-16 does not have a 10m2 frontal RCS.

Btw how about jamming effectiveness as reduction of RCS ?

No. Because ECM signals contributes to RCS.

This statement tells me you have an incomplete understanding of how the RCS process works.

https://en.wikipedia.org/wiki/Radar_cross-section

The general understanding of RCS involves 'radar' as in a type of signals that are created specifically for the detection process.

Unfortunately, that general understanding is incomplete.

If you transmit a simple HF communication chirp, the seeking radar will pick up that chirp and add it to what it have of you, that equals the final RCS. In other words, the real RCS is a COMPOSITE of many EM signals that maybe produced by a target. That is why the F-22 and its cousins have strict EM protocols in combat.

ECM signals is essentially a beacon telling everyone 'Here I am'. Pretty much defeats the purpose of 'stealth'.