Tällainen osui silmiin Rafaleen liittyen:
*edit. Linkistä mukavampi lukea. On tekstin lopussa.
Factor 5 : Stealth and SPECTRA.
In the early’80 s, the DGA (French procurement agency) and Armée de l’Air started studied the self protection system of the future combat aircraft.
Future threat analysis as well as cost considerations (acquisition and maintenance) led to a compromise between high kinematic abilities and the different parries to theses threats.
· Preventive avoidance led to full spectrum signature reduction features, automatic very low altitude and very high-speed terrain following ground system and adaptation of pathways using a sophisticated mission preparation system.
· In-flight detection of threats and adapted course change, allowing real time adaptation of preventive avoidance.
· Avoidance by neutralization – jamming, decoying and ultimately destroying threats.
Whole Spectrum Signature reduction measures are obtained by several means, mostly classified, some documented. In the IR spectrum for example (heat detection), there is a supplementary cool air channel around the engine exhaust. In the radar spectrum, extensive use of composites (1/3rd of the plane mass, 70% of the wet surface (that is roughly to the same extent as the future Pak-Fa Russian fighter)), and RAM coatings, presence of serrated “saw-tooth” patterns on canards and wing trailing edges, as well as inside air intakes. Instead of deflecting incoming radar waves to an angle away from the emitter, they are channeled towards “spike” points heavily treated against reflection. Dassault engineers do not claim their plane to be “stealthy”, but very discreet or “sneaky.” All in all, the Rafale has a radar cross section reduction by 20 times compared to the Mirage 200015.
Avoidance of known threats is obtained either by mission planning (and the data will appear on the tactical display) or in real time, via Link 16 or detection by any of the plane sensors. In the latter cases, SPECTRA is able to propose actions vs. emerging threat, be it bypassing via recommending a new route to the pilot in order to avoid lethal areas (sophisticated enough to take into account the characteristics of the threat and topography), jamming, decoying or destroying the threat.
Here lies the origin of the SPECTRA concept, which most modern EW suites are only now emulating. Far from being a simple “situation Awareness” suite, SPECTRA is capable of offensive actions. It has 3 AESA highly directional jamming antennas allowing deception jamming. The possible types of jamming involved have been extensively discussed on the net and are highly classified. We know it uses a DRFM (Digital Radio Frequency Memory) chain and “intelligent” jamming instead of “brutal jamming”. False range targets, velocity gate pull-off, and narrow band Doppler noise created by using digital RF memory (DRFM) are the common coherent EA techniques which can be used effectively against LPI radars23. Simply put, it is able to feed enemy radar with wrong data about presence, location and number of planes. It acts as an illusionist instead of using noisy, blinding “projectors” (“broadband white noise jammers”). Furthermore, depending on conditions, SPECTRA is able to detect and localize potential threats accurately enough to allow a shooting without using active (detectable) sensors. Some interesting results nevertheless leaked to specialized press, here are some:
· While flying over Libyan air defenses (before the Libyan air defense system was suppressed by tomahawk salvo), Rafales planes “poofed” from enemy radars31.
· During NATO Mace XIII exercise in Slovakia, a Rafale B flew unmolested over a S300 radar (and was the only type engaged in the exercise able to do it)21
· During Joint warrior 2013-1 exercise, rumours say SPECTRA literally gave headaches to Eurofighter’s Captor M radar, preventing it from tracking visible and detectable Rafales.
· During his test flights in 2012, DefesaNet test pilot Vianney Riller Jr. could shoot, entirely relying on aircraft passive sensors, a plane attacking him in his 6 o’clock position from way over 10 NM. At the moment, as far as I know, Rafale is the only operational plane able to perform such a shot.
· In a 2011 technical presentation brochure at Le Bourget, “virtual stealth technology” is stated27.
SPECTRA is completely integrated to the airplane (and will react differently according to the plane configuration). This is a very important feature as the suite wasn’t added to the plane like a jamming pod would, but was designed for the plane as a coherent system (with exact radar behavious, IR signatures and loads in mind).
This advanced, integrated EW capability is another area where the Americans are actually playing catch-up. The Rafale is the only aircraft delivering this advanced combat capability on the market today. The Boeing EA-18G Growler, the electronic warfare variant of the F-18 Super Hornet, will only be getting this capability in a next generation external jamming pod from Raytheon on 2020. In order to have the air-to-air, air-to-ground AND EW capabilities at once, you need to fly both the SuperHornet and Growlers – two jets compared to one Rafale.48
In conclusion, instead of relying completely on a stealthy shape, Rafale relies on a smart avoidance system and highly sophisticated sensor suite, real time mission planning and top end AESA jammers. It is noticeable that in 2014, a Rafale demonstrator will fly with gallium-nitride (GaN) made SPECTRA antennas, a world first, demonstration the involvement of French state in constantly upgrading the aircraft. Again, this will be six years ahead of the Growler getting that capability and only promised on the F-35.48
http://blogs.ottawacitizen.com/2014/03/05/the-rafale-as-canadas-next-fighter-part-2/
