Wrightwing :
The ping will make it back before the signal is analyzed, identified, and the jammer sends a signal of its own.
Yes .
You see that I am with you on this one , because of Physics laws .
What you don ‘t seem to understand is how an Aesa radar works in the first place , secondly you greatly underestimate Bragg Cells and to a lower extent Superheterodyne .
An Aesa radar need multiples reflected “pings” to build a picture . Thousand times per seconds , an Aesa radar send multiple (hundreds) “pings” on various frequencies and hope to get enough “returns” to buid the picture .
That is how it works .
Bragg cells are basically “mirrors” , they can reflect back the exact signal received (to make it short) but it would be of no use , obviously .
That would make the reflected signal even stronger 😡
What can be done in a matter of nano-seconds (using a simple line of C++) is to change the phase of the signal (active cancellation) and “reflect” it with optical cells (Bragg) in almost real time .
This is doable and has been done against old radars but the problem lies elsewhere .
“Active cancellation” is a big thing and I don ‘t think that the rafale is using it as we speak (May 2010) .
To archive the trick , one needs to know pretty well the planned RCS of the fighter at some critical angles , with and without external stores .
A couple of months in a good anechoic chamber and some various 3D CGI tests will provided what is needed to start to work on it .
In fact , I am repeating myself . I have been through this before 😎
Never mind …
The real challenge is to be able to “mimic” and “duplicate” that out-of phase signal simultaneously on many bands carefully chosen with 3rd gen DRFM techniques . So far , it seems that Thalès has its hands on something 😎
*****************
Now , let ‘s forget about “active cancellation” and let’ s have a talk about May 2010 😉
If the Rafale were 200km away, it wouldn’t be considered a threat yet, first of all, as the APG-77 prioritizes targets by range, and the amount of time that they are illuminated and subsequently tracked. Secondly, it would take more than 1 ping to correctly identify what the ping was, much less respond to it.
At 200km away , the Rafale wouldn ‘t be considered at all while Spectra would consider the “pings” .
As I said , thousands of “pings” can be stored and analysed in matter of seconds and/or minutes .
This shows a fundemental misunderstanding of how the APG-77 works. It doesn’t send out constant broadcasts to the maximum range that it can achieve. It might do a brief periodic sweep to see if anything’s out there, but until the target gets within a certain distance, its track is only periodically updated. It doesn’t get a constant track until it’s within range to engage.
We know that a radar is working differently when is it scanning than when it is tracking , obviously (again) . That also means that less “active modules” are used for long range detection than when tracking .
It is precisely where a top notch RWR does marvels . 🙂
Spectra :
First , it will warn the pilot that an adverse radar is scanning from that sector and at long range (very low signal) . The pilot can turn 30 degrees left or right and stay outside the detection range while still listening the “pings” . No need to jam , we ‘re not detected yet …
(What a huge advantage it is already in BVR)
If the adverse fighter is flying high and fast (T-50 ? Mig-31 ? SU-27/35 ?) , it could end-up close enough to get a positive lock .
From there on , the radar would try to get a track and a firing solution .
To do that , the adverse radar will change “modes” from detection to tracking . It will start to send many more “pings” (thousands) to try to get the best available picture to display to the pilot . If it is a good Aesa array , it will also “lock” some frequencies with ECCMs to try to keep the “lock” at all cost .
This is where Jammers are having a problem 😮
Deceptive active jamming with beam forming (active phased array) have great difficulties to “fool” the ECCMs . One have to understand than the “locked” frequencies chosen by the adverse radar software can change very rapidly and unless the jammer can “blanket” the most obvious frequencies , few “pings” will help the adverse radar to keep the lock .
Fortunately , a well made active phased array jammer will simply respond in time where the most obvious PEAKS are . 😎
In doing so , very few “workable” “pings” will reach the adverse radar .
*******************
Lindermyer , I ‘ ve never bashed the Typhoon .
I only say that the Rafale is a better overall fighter with a lower RCS , better sensor and integration , better MMI , better ECMs , better A2A capabilities , better A2G capabilities and it is carrier capable . 😎
I am not bashing .
Cheers .
Sign In
