> The F-15C was using a Commodore 64-level processor in the APG-63
The F-22 is a different animal, its radar changes frequency and power level with each pulse and the F-22 has only one computer, not a computer for each major systems. The F-15 has a flight dynamics, fire control, radar and, a couple of others. The F-22 has just the two computers that the USAF says has the computing power of a cray supercomputer, that statememt is made for a reason.

Hmm… “each pulse” is a bit of an exaggeration – changing frequency and power level that often would preclude the integration necessary for High and Medium PRF operation.

As for Cray supercomputers, I recently saw two of these museum pieces being used as stylish cafeteria benches at a European university. Just like “insect-level” radar cross section – sounds good for reporters, but really just a way to avoid the inconveniences of an actual numbers.

-SK

Unless you are in the Russian AF or ex-Soviet airforce, there is no way I deem you more reliable than the source who told me.

The more secret a source is, the more wrong it is. (See: Iraqi WMD) Anything true can stand up to cross-checks and scrutiny.

Of course they could make good missiles too. Like with the anti-tank missiles. The ones working for the test-firing exercises are mostly well made. But when it comes down to regular production units, the missiles are rubbish. That’s because the quality control doesn’t work in Russia.

Be advised that Russian and ex-Soviet Shturm operators have spoken to the falsehood of this. If you don’t consider these sources reliable, then why lie and say that you do?

So basically in a real time firing exercise, yes, the missile might have not exploded. But when production units were test-fired in Iraq, they all missed or exploded in mid-air.

Even dog carcasses explode in Iraq. Nobody blames the manufacturer.

Liquid missile fuels are highly reactive and corrode their containers. Correct operating procedure is that the missiles are not to be fuelled until just before the mission is flown. Explosions in flight are indicative of someone not reading the instructions.

-SK

A single-engine fighter usually outranges a twin-engine.

F-16 outranges F-15 and F-18,
MiG-23 outranges MiG-29.

-SK

You’re right, it’s an oversimplification. But then, does HPRF (high frequency PRF) which gets more hits per sweep, also has less range due to shorter/weaker pulse? And lower PRF does the opposite?

HPRF has longer detection range, but measures that range less precisely.

HPRF RWS and I believe TWS also adds an FM carrier wave, and the changes in FM wave is used to determine radar range. But that reduces range as well.

Most HPRF modes use FM ranging. It reduces the detection range compared to VS (which is also HPRF but without FM ranging), but it should nevertheless be longer than MPRF. The accuracy of FM ranging, however, is determined by the resolution of the Doppler filter bank and the rate at which the FM is swept. Much more so than by the radar’s X-band carrier frequency.

When you further go into modes used for locking and tracking targets for guided missiles, you’re into FMCW techniques, at least from my understanding. SARH missiles like the Sparrow, and ARH missiles like the AMRAAM all use CWI techniques.

The recent AIM-7M versions and the AIM-120 have monopulse antennas.

-SK

That poor resolution in range (up to 8 km) is due to the frequency of the radar or antena design. How much reduction in estimation error for range can be achieved by going to PAR type antennas.

The range resolution depends on operating mode, but not really on operating frequency or antenna structure. Some range imprecision is an inherent property of High PRF and affects US radars as well (e.g. in HPRF Velocity Search mode, which has the longest detection range, there is no range data provided at all). Fully automated digital radars are better able to mix their PRFs and operating regimes to overcome the weaknesses of individual operating modes – e.g. “Raid Assessment” and HDTWS modes which alternate “search” and “spotlight” operation to reduce the range uncertainty of “search” alone. The Russian radars are switched manually between High, Low, and Interleave, the latter of which can’t be used with TWS.

Aren’t lock-on ranges always, some what less, than detection ranges (probably due to the initial poor S/N ratio of the signal, when the target is much farther from radar).

Amplitude monopulse antennas create two (or more) beams pointing in slightly different directions, and compare the signal strength from each beam to determine which way the target is moving. A “locked” target centered between the beams is not at the position of maximum sensitivity of either, so the target needs to be a little closer to be locked than it does to be detected. Phase monopulse antennas have the beams pointing in the same direction, so a target can be locked at practically the same distance it can be detected.

Compared to “west”, how far are “russians” behind in radar technology.

This is an awkward way to express the question because the Russian forces stopped receiving any new fighter radar technology at the end of the Cold War. What is the estimated arrival time of something that is stationary?

But for discussion’s sake I would say design bureaus – “5 years”, air force – “30 years”.

How much improvement can be extracted from these poor radars by subjecting them to a heavy dose of “digitalisation” (e.g. using better CPUs and DSPs)

Switching from large numbers of analog filters to digital sampling would replace all of the radar circuits. It would be more cost-effective to build something completely new.

My opinions,

-SK

The Russians and Americans have different views on aerial combat to start with. The resources each country has is also very different.
In the past and it looks like in the foreseeable future the friends of Russia will have to defend their airspace. The friends of the American aircraft tend to be the countries who export the fight to their neighbors.
This is reflected in the overall design.

I wish I had enough rank to add to somebody’s reputation because this is IMHO among the best written answers I ever saw online about Western vs. Russian fighter radars, and it didn’t receive nearly enough praise in this thread.

About the only part I would disagree with is the part about Russian radar azimuth search. In general the scan azimuth is fixed at +-25 degrees and can’t be widened, only the scan center can be shifted left and right. This corresponds with the Soviet GCI design principle that the fighter radar is not intended for target detection, but rather for missile fire control.

Back to the original question though, some specific weaknesses of the Cassegrain antenna-based N-019 and N-001 compared to US-built radars with mechanically scanned slotted arrays:

– Heavier radar
– Heavier antenna
– amplitude monopulse instead of phase monopulse
– lock range is shorter than detection range
– lock is not instantaneous
– no ground mapping modes
– based on large number of analog Doppler filters instead of digital sampling
– larger Doppler “notch” range of blind speeds against beaming targets
– sidelobe compensation guard channel horn doesn’t rotate with reflector
– sidelobe compensation needs to be manually switched on
– sidelobe noise reduces detection range at low altitude
– sidelobe noise creates additional pursuit “notch”
– poor resolution in range (up to 8 km) and azimuth (up to 10 degrees)
– reduced downward-scanning antenna gimbal limit prevents missile lofting
– reduced downward-scanning antenna gimbal limit complicates F-pole tactic
– no NCTR mode
– display doesn’t provide sufficient data about target altitude/speed/direction
– no pulse mode for look-up targets

The Russian jets are also generally disadvantaged in BVR for depending on limited-range SARH radar missiles which can’t be fired from TWS mode, lacking active jamming equipment, and some other issues, although these depend on the exact aircraft under discussion and are separate from the radar itself.

Despite the long list of disadvantages however, the coherent LD/SD radar closed the “back door” in the Soviet air defence network that was previously open to low-altitude NATO strike aircraft, and thus smashed the enemy’s spear in a way perhaps no Soviet invention had done since the atomic bomb – the NATO armadas of A-6, F-111, B-1B and Tornado IDS all became instantly obsolete. This is an accomplishment not fully appreciated by the question “who would win in BVR”.

-SK

Once all you fighter pilots are done answering this question amongst yourselves, be sure to head over to some army forums and tell them how it is.

😉

-SK