After the F-15 Silent eagle its time for Su-30MKI to disapear out of the radar. There have been reports that Russias UAC (United Aircraft Corporation) and Indias HAL (Hindustan Aeronotics Limited) are developing the Smart Skin concept for Su-30MKI.
More like 'rumors'.
Smart skin also know as Artificial neural membrane refers to a new class of functional structure developed through research adaptive and evolutionary neural networks and programmable materials. The greatest interest in ANM structures surround their potential as open architecture environments for the integration of microscale and nanoscale devices. Artificial neural membrane technology development has been funded by the NASA Institute for Advanced Concepts, for application to quasi-steady state flapping wing flight. Currently Aerospace Research Systems, Inc. the agency that pioneered work in developing artificial neurons for use in control of multifunctional smart structures is applying the technology to reusable launch vehicles. Other applications include biotechnology processes, morphing aircraft and spacecraft, adaptive wind generators, and artificial organs. Recent research also indicates that ANM systems may provide the first truly automated intentional or conceptual programming environment.
By 2014, UAC together with HAL will begin upgrading the first 100 IAF Su-30MKIs by modifying their airframes to make them stealthy, converting the existing Bars into an active phased-array radar, enhancing the situational awareness by incorporating active electronically scanned transmit/receive arrays on the aircrafts wings and pumping up the defensive-aids suite by installing a combined radar/laser warning system and a missile approach warning system.
The US is already working on active RCS controls for future and even current airframes without entering SyFy territory.
To have a basic understanding of how the new techniques work, it is useful to have a basic understanding of how passive measures works...
Radar-absorbent material - Wikipedia, the free encyclopedia
Radar absorbent material, or RAM, is a class of materials used in stealth technology to disguise a vehicle or structure from radar detection. A material's absorbency at a given frequency of radar wave depends upon its composition. RAM cannot perfectly absorb radar at any frequency, but any given composition does have greater absorbancy at some frequencies than others; there is no one RAM that is suited to absorption of all radar frequencies.
A common misunderstanding is that RAM makes an object invisible to radar. A radar absorbent material can significantly reduce an object's radar cross section in specific radar frequencies, but it does not result in "invisibility" on any frequency. Bad weather may contribute to deficiencies in stealth capability. A particularly disastrous example occurred during the Kosovo war, in which moisture on the surface of a F-117 Nighthawk allowed long-wavelength radar to track and shoot it down. RAM is only a part of achieving stealth.
Pay no mind to the blurb about Kosovo, it is a misunderstanding on what happened. Rain do not degrade the absorber materials
per se but rather create irregularities on the body's surfaces that the behavior of a radar wave will inevitably amplify the body's RCS at that particular aspect angle to the ground radar trying to find the aircraft.
Theoretically...On a perfectly smooth surface, specular reflections will not return to the transmitting radar and the aircraft would effectively be 'invisible'. That is how radar behave on a surface -- that if the surface is angled off 90deg from the transmitter, any deflections will be 90deg off the surface. That is why the F-117 look the way it is -- angled faceting.
But since no surface is perfectly smooth, we have a blend of specular and diffuse deflections off a surface and it is the total of diffused deflections that a radar will detect an aircraft. That is why on the ground, maintainers are required to wear boot covers so they do not create even microscopic gouges on the surface that could add to the overall RCS value.
On to absorbers...
There are four main types of absorbers:
- Jaumann layering
- Dallenbach layering
- Salisbury screen
- Analog circuit sheeting
The first three absorbers are passive. They contain ferrite particles in a film or liquid. The particles' sizes and density affect certain freqs but often their distribution are not uniform in said film or liquid. Layering the types together to increase bandwidth will increase the aircraft's weight. The absorbers are delicate but they cannot be 'destroyed' by weather or even bare boots as popularly depicted in popular media, especially the ones who are desperate to downplay the US accomplishments. Rain or sheets of water flowing across the surface will create higher strength diffuse reflections (or deflections) and will increase the aircraft's RCS -- for that moment. Extreme temperature variations can create microscopic 'wrinkles' or 'ridges' that are no different than what is on plain steel or any alloy and of course add to the diffuse reflections. So do dismiss any stories on how US 'stealth' aircrafts are oh-so-vulnerable to weather that could 'destroy' their absorbers.
Analog circuit sheeting are intended to be patterns of ferrite particles in varying sizes and in uniform distribution in a material. Analog circuit sheeting are more complex to manufacture, currently are also passive in operation and is equally vulnerable to surface irregularities like the other three absorbers. But analog circuit sheeting can be designed the same ways semiconductor circuits are created -- photolithography.
Photolithography - Wikipedia, the free encyclopedia
In essence, transistors are created with a thickness no more than that of the other three absorbers. Transistors are active. They can amplify or ground a signal. Analog circuit sheetings have been created with patterns as complex as crosses and the potential for having zero RCS at any aspect angle is very real. For the crosses, their thickness affects the resistance of the sheet, their physical dimensions affects the inductance of the sheet and their spacings affects the capacitance of the sheet. Not only that, imagine a set of four crosses, now imagine a radar signal bounces around in the center of this set, escape through one of the gaps, trapped again by another set and eventually the signal die from energy loss. Make each cross an active transistor and we have 'smart skin' without resorting to none of that 'neural network' nonsense propagated by Russians desperate for sales and validations.
With active RCS controls, an aircraft, drone or manned, can be invisible one moment and as large as a B-52 the next. The defenders will be no wiser. The defenders can be certain that they are facing attackers who can manipulate their RCS but the defenders can also dismiss the real 'non-stealth' bombers, B-52s or B-1s or even a lowly Cessna 172, that are sneaking up on the targets while the radar operators are distracted. The defenders can respond to a flight of real B-52s but then be attacked in another direction by 'stealth' attackers who were invisible to their radars.
i didn't said the upgrade is gonna make MKI a stealth fighter ! but the new smart skin and internal wepons bay could help in reducing radar signature of MKi.
