There’s nothing wrong with this picture.
However, lower frequencies’ (long waves’) power drops off slower than higher frequencies’ and in the end, actual radar systems (in use) represent technical/requirement solutions of that.
So, this is always as trade off and you can have large antenna (high gain) and small power, or small antenna (low gain) and high power, to achieve reading at required range, against required target size.

Thank you! That makes perfect sense. It would also explain why various platforms seem to get away with the ‘stealthy’ title even if there are visible small gaps, bumps, antennas etc present on the airframe. Those may be picked up by higher frequency radars like in the missile’s homing head but not as easely by search radars, right? Of course, higher frequency radar is easier to neutralize with RAM, as a thinner and lighter layer is enough for it, so those little bumps and gaps may be the only thing sending back any meaningful signal.

http://www.tscm.com/rcs.pdf
So there was this link posted, about RCS theory.

On the very first page it has an illustration showing that a 0.093 * 0.093 meter plate will have a RCS of 0.01 m2 at 1 GHz, but 1 m2 at 10 GHz.

(in offers another example showing those values are linear – where a 1 * 1 meter plate has a RCS of 14.000 m2 for a 10 GHz radar and 140 m2 for a 1 GHz radar.)

Now, does that mean that if we use an X band radar of 10 Ghz and point it to a fighter, we will get a RCS of X*1, while if we use a lower frequency radar like L band working at 1 GHZ we will get a RCS of X*0.01? X, naturally, being all the other variables that have anyhting to do with the radar return but they’re unimportant as they’re the same for both radars.

So lower frequency, longer wavelength radar will always get a 100 times smaller radar return, regardless of the physical size of the object???

What is wrong with that picture? I’m sure I’ve missed something but I don’t know what. Help?

One thing that seems clear to me is that Pak fa is designed for slightly higher speeds than raptor (nose and wing sweep angle) and is more akin to original YF22 design in that regard.

Those weapons door bays are about 5m long. Central bays 5,1m long…
(Unconfirmed).

If true, this mean it get to carry some big BVR missile, depending on how the missile ramps inside are configurated..

Those figures don’t really mesh with certain other comparisons. That f22 over pakfa image suggests length is around 18.5 to 19 meters. That also coincides with the width of the engines on the pak fa, which are said to be further developed 117s, which in themselves are a version of al31f. If bays are 5 meters long then the engines would be significantly longer and wider than 117s.

In line with 18.5 to 19 meter length i suggest actual weapon bay doors are closer to 4.4 meters long and some 1.15 meters wide.

Interestingly enough, it’d mean pak fa has a huge wingspan for its length, of over 14 meters, perhaps over 14.5 meters. (and if we accept the 21-22 meter lengths which were a product of just assuming the existing su27 length – we’d get a monstrous wingspan of over 16 meters!)

I used the one picture where the plane is shown taxing, from the side, and there are a bunch of people arond it, in front, behind it, etc. From so many people one can deduce the average height. Now *IF* the average height is 1.80 meters, then the plane seems to be around 18 meters long, from the tip of the nose (without the pitot tube) to the tip of the tail sting. Also, it would appear height from the landing gear tyres to the tip of the vertical stabilizators is some 4.7 meters. Now, if we take those values for granted and use them on the picture where we have the plane flying in the air, seem almost from above, we can kind of deduce the wingspan – which would be around 14 meters.

Comments?

Those fairings near the wing root do seem peculiar. The left picture seems to show a bit of a gap between them and the wing though. Could it be they are some sort of pod for various EW equipment? (here, of course, thered be only stand-in structures, but later on they’d tack on real equipment)

How credible is the 960 micas for taiwan claim? It’s being thrown around the internet at various websites but none actually link the claim to any sort of a source. Claim is even less believable when it mentions missiles were delivered in the 90s. Officially, first EM micas were ready by 1996 and first IR micas by 2000 but when one starts to dig out details it seems full scale production began even later than that. Here are bits from a newsbit from MBDAs own website, dated january 2001.

“Matra BAe Dynamics has just been awarded a 2000 budgetary year contract worth 250 Million Euros (£ 150 million) by the French DGA Procurement Agency. This contract is for the mass production of air-air MICA missiles, both for the French Air Force and the French Navy, starting in 2004. It is the first batch of a potential 900 Million Euro (£ 530 Million) global order. In the long term, the MICA (interception, combat and self-defence missile) will be the sole armament of the Rafale and the Mirage 2000-5, covering all of these aircraft’s short- and medium-range air-to-air missions.

The initial MICA EM missiles intended for the Mirage 2000-5 of the French Air Force were mass-produced in 1999 by Matra BAe Dynamics. The Mirage 2000-5/MICA air defence weapon system has already demonstrated its air superiority during international exercises.

The MICA EM is also operational in Asia and in the Middle-East, on Mirage 2000-5. The Mirage 2000-9 of the UAE and the Greek Mirage 2000-5 Mk2 will also be equipped with the complete MICA EM and MICA IR weapon systems. “

edit: just found an interesting report that seems fairly credible concerning mica production. http://www.forecastinternational.com/samples/F659_CompleteSample.pdf

Now, while it is perfectly possible that taiwan did order 960 micas, such a quantitiy would for sure mean most of them are barely 5-6 years old. Even the oldest missiles are 9 years old, if that. On the other hand, 960 micas for 60 some planes is a ratio of planes to missiles that i havent seen anywhere else. In the end, the linked report itself suggests, though again without links to sources, a more credible solution – 480 micas (alongside 960 magic 550s, which in itself is again a somewhat bewildering number)