J-20... The New Generation Fighter III

I see -- but if we're talking J-20's radome, I think this picture illustrates it most clearly



There also seems to be some sort of long panel on the right side of the cockpit, which says to me it could be an IFR probe. But it's so faint, and there are undoubtedly many other similarly shaped panels it could be anything.

Gentlemen, I believe you are correct, since somewhere I am certain its is written, in the law of the medes and persians, that with the advent of the jet-age, that all forward facing radar sets, would be located on the forward fuselage bulkhead/firewall, covered by the most elegant piece of fiberglass imaginable. I know someone will feel compelled to correct me, but the F-86D, had a radome above the turbine inlet, this from memory, so if I'm wrong it won't be the first time. This is one of those, "and as their custom was" sort of issues, in the 1980's in a desire to install radar on single engine propellor driven aircraft, a pod was available, slung under the wing on Cessna hi wing aircraft, and molded into the leading edge for low wing aircraft such as the Beech Bonanza family, and Piper Saratoga. This is first and foremost the most practical location, the other issue with such a purported increase in power for the J-20 radar is heat, the enemy along with moisture of all electronics, while it is tempting to increase wattage, it "always drives up heat"? So I find it doubtfull that there has been that kind of increase in peak power.

or this one:

When I talk about an increase in peak wattage, I only mean for specific detection modes; you only need to burst a high-energy signal for less than a second to achieve "peak wattage". And that does not necessarily generate high heat; as long as you make the burst short enough.

It doesn't necessarily have to mean an increase in tracking range, all that's needed is a significant increase in detection range. You get that, you pack in an AWACS-killer missile, and blam, you have a dead AWACS. It would also be useful as a way to burn through jamming; if you have a bunch of ambiguous signals, a few bursts at high peak wattage, then you can confirm which of your signals are ghosts and which of your signals are actually aircraft, then switch back to the normal emissions mode.

I suppose it's the opposite of low-probability of intercept radar, but it could be useful.

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Regarding the radome, as I've mentioned before, the radome size would be very useful. If we know precisely what the radome dimensions are, we can get an estimate of the radar dimensions then extrapolate a likely radar detection range based on known technologies.

All well and good, but to increase wattage you have to increase the size of wireing, connectors, and heat sinks. If you increase the power 5x you have to increase the ability of all those systems to handle the increased load. We've all experienced voltage spikes and those of us who do play with our own toys have seen the results, the melted wires and connectors, and sometimes fires and while most of the time you can kill an electrical fire in a vehicle by killing the juice at the master switch, you risk loosing flaps, gear, and in the J-20 all those sweet flight control computers that make her do what she doen't want to do, which is to behave herself. I'm rather certain that its more likely bad info, but I don't have any sources, just a hunch. In the states if you say something is so, it better be, otherwise its fraudulent and the taxpayers don't like to be lied to, propaganda is distinctly frowned upon in this culture. Now a guy may lie and say his car is faster than it is, and civilian manufactorers do make exagerated claims, the military usually declines to name specific capabilities for classified projects. As a point of fact the Pak-Fa's as demonstrated at Maks 2011 did not have radar equip installed, and while many of us suspect there are likely two J-20s, this aircraft remains a far distance from being operational, and the final equipment list and armament consists of many pieces which are not operational as well. We don't even know for certain the powerplant scheme for production aircraft, and while thrust vectoring and super cruise are design objectives, the only operational 5th gen in the world has had her feathers clipped by the kool-aid drinkers. So sit back in your easy chair, pour yourself another tall cold glass of kool-aid and I'll do the same, I prefer Air Force Blue. The other thing you really should think about, is that most stealthy millitary equipment, ships, submarines, and aircraft go to great pains not to emit radar waves, as it just advertising where you are. If you go looking for the F-22 and light up that fancy radar, you will definetly find something, but it won't be the F-22.

Inst said:

When I talk about an increase in peak wattage, I only mean for specific detection modes; you only need to burst a high-energy signal for less than a second to achieve "peak wattage". And that does not necessarily generate high heat; as long as you make the burst short enough.

It doesn't necessarily have to mean an increase in tracking range, all that's needed is a significant increase in detection range. You get that, you pack in an AWACS-killer missile, and blam, you have a dead AWACS. It would also be useful as a way to burn through jamming; if you have a bunch of ambiguous signals, a few bursts at high peak wattage, then you can confirm which of your signals are ghosts and which of your signals are actually aircraft, then switch back to the normal emissions mode.

I suppose it's the opposite of low-probability of intercept radar, but it could be useful.

===

Regarding the radome, as I've mentioned before, the radome size would be very useful. If we know precisely what the radome dimensions are, we can get an estimate of the radar dimensions then extrapolate a likely radar detection range based on known technologies.

Click to expand...

If we go by that faint separation on the nose, then it's a pretty big array...

Here's a video taken on Feb 4th.

Doesn't increasing peak power of the RADAR make the aircraft more vulnerable to system like the AN/ALR-94 or even your regular RWR? One analogy I read at AFM about the Irbis-E (N035) was that when the N035 is operating at peak power, max-range (rather slow scanning) is like a lighthouse in full glow for ships. Even the F-22 has special modes and in LPI mode the detection range is lower.

Hyperwarp said:

Doesn't increasing peak power of the RADAR make the aircraft more vulnerable to system like the AN/ALR-94 or even your regular RWR? One analogy I read at AFM about the Irbis-E (N035) was that when the N035 is operating at peak power, max-range (rather slow scanning) is like a lighthouse in full glow for ships. Even the F-22 has special modes and in LPI mode the detection range is lower.

Click to expand...

Peak power is a specialist mode only used during engagement of enemies who are employing strong, active jamming, or a few other specialist applications, and only ever for very short bursts (so both sides only gets a peek at each other, if you will excuse the pung). In which cases, the enemy already knows are you out there, and the bursts are so short that enemy RWR and EW would not be able to generate a useful targeting solution for them to take a shot at you be homing in on your radar.

After your peak power burst, your inherent stealth advantage would still count, as your fighter would be moving so fast that any speculative missile shot fired at the last point where the peak power burst came from would have no chance of hitting you (since you should have pull away and established a new approach vector as soon as you made your peak power peek). OTOH, as Inst already pointed out, your own peak power burst would have burned through any active jamming a conventional fighter might have put up, and you would know which of the returns to shoot at when you are in range and ready.

Even fighters using their radars in normal modes will be like a lighthouse at night to enemy RWR and EW suits, which is why LPI modes were developed - so that fighters could actively scan for enemies without giving themselves away. But with modern developments in digital RWR and ECM gear, even LPI modes may eventually useless in the not too distant future, if it isn't o already.

Hyperwarp said:

Doesn't increasing peak power of the RADAR make the aircraft more vulnerable to system like the AN/ALR-94 or even your regular RWR? One analogy I read at AFM about the Irbis-E (N035) was that when the N035 is operating at peak power, max-range (rather slow scanning) is like a lighthouse in full glow for ships. Even the F-22 has special modes and in LPI mode the detection range is lower.

Click to expand...

You are correct sir, even a quickflash would advertise your position, we can all engage in hypotheticals, but for those who think they would like to see a J-20-Raptor head to head, its interesting and I admit to a certain academic curiosity, only because I'm fairly certain how that would come out. Truth be told thats one reason I like to see a great deal of parity, as a child of the cold war, it seemed to have kept everyone from doing something really stupid, I would like to think all my brothers on Sino Def are of a higher caliber than average. The airshow is still the proper place for these beauties, as the best weapon of all is one you don't have to use, but to be honest I think our Russian Bros will take all the risks, as Maj Max the first Raptor demo pilot pointed out, they actually departed their aircraft a low altitude, looks awesome, and it is risky, but not something one would do in a combat scenario, and not something a USAF pilot would do during an airshow. I would be very hesitant to speak of the Raptor in the perjorative, or to have a desire for any other bird to go head to head with it, as it may be old school, but it is very, very good! As a point of fact it remains the "only operational fifth gen". Carry On gentleman.