معلومات تفصيلية عن السبيكترا تحتاج تركيز كبير للمهتمين :
This post is to upgrade the knowledge about Rafale taking into account the PEA DEDIRA.
DEDIRA means Descreet Rafale Demonstrator, and was done in addition to the INCAS program to improved the SPECTRA suite:
Current rafale development programs known :
TREGEDAC : passive detection improvement via aircraft networking
INCAS : Spectra improvement including GaN + active decoy against Ka band missiles
CARAA : improved RBE2 AESA with new modes and better performance
DERIDA : stealth increase
GANIMEDE : GaN modules industrialization
PEA MELBAA : New modular architecture for radar calculator, new generation electronic countercountermeasures (CCME) ...
MFA: Multifunction antenna : Multi Function Array GaN ...
At the begining DEDIRA was believed to include modification of the air intake shape, use of conformal weapon containers and New RAM technology to hide weapons. But insider information says that DEDIRA is already working (and working well) on the B 301 airplane. Because there is no structural modification on this plane it could only be a added SPECTRA effect.
Then the surprise comes from Revellin Falcoz-revealing information that he describes as "classified"
SPECTRA is more than just an_ ECM / ECCM suite although from a hardware perspective, it uses known and controlled by others than the French technologies. Its main features are that it is:
• Powerful,
• with multiple antennas, well sized,
• With a database which is an essential element of the system
• and with the tools to gather information and analyze them before sending them to the pilot.
But what makes the originality of SPECTRA is to have both interferometric detection, interference by AESA dedicated directional broadband antenna and coupling jamming diagram and SER.
Interferometry saves more than 10 in location accuracy compared to conventional detectors factor, this requires placing the antennas on rigid parts of the aircraft.
Under these conditions we have the following improvements:
• a bearing will have a precision of less than 0.5° against 10° for conventional detectors (normally interferometry allows 0.1°)
• The same factor of improvement is possible with TDOA
This accuracy facilitates spatial discrimination of LPI signals and allows the directional jamming.
The low Rafale SER (LO rather than VLO) plays a role in facilitating jamming by SPECTRA. This possibility is meant "coupling SER / Jamming."
Indeed, if the SER decreases, the power to make deception also decreases which makes better use of the available power. Additionally using the directivity of the jamming the power required is further decreased and we can multiply the number of sources that can be treated.
As an AESA radar antenna, AESA jamming antenna can be split to jam several sources.
The Rafale does not need towed decoy as directional jammers can use reflection signals sent by SPECTRA on decoys dropped at the computed time.
The strength of by SPECTRA is:
• AESA jammers with flexibility and growth potential, particularly to the GaN components
• integration into the weapon system where others had merely at best a "hierarchical" fusion (RWR inform the other sensors), the Rafale operates "cooperative": each sensor contributes to the overall picture and several "weak" sensors can be combined to get a pretty good track for a firing solution without the need for a "strong" but not very discreet as the radar sensor.
How does SPECTRA work?
First you need to know perfectly the "signature" of your own aircraft. Due to the complexity of the SPECTRA traitment, Rafale start to simplify its signature: the aircraft is designed so that its untreated radar signature is concentrated in a few strong "spikes," which are then "attenuated" by the selective use of RAM. The collection of these few strong spikes are the "model" of Rafale.
Second it would be nice to cancel the reflected radar signal. The original incoming signal from the radar will be reflected from the spikes. Each spikes will produce an individual reflection with its own, often unique, amplitude and phase. The return signal, picked up by the radar, would look somewhat chaotic, consisting of background noise and "spikes". By removing these "spikes" from the radar screen the aircraft may blend in with the background noise, which is normally ignored by the radar operators.
If you look at where are SPECTRA active antenna, surprisingly they are close to areas that can generate spikes.
To remove these spikes the aircraft, when painted by a radar, transmits a signal which mimics the echo that the radar will receive from the spikes, but one half-wavelength out of phase, so that the radar sees no return from them. The advantage of this technique is that it uses very low power, compared with conventional EW, and provides no clues to the aircraft's presence; the challenge is that it requires very fast processing. This fast processing was demonstrated by Carbone.
@House 
