The art of radar deception: invisibility cloaks for military equipment
Masking
The developer of the new camouflage radio-absorbing material for snow backgrounds is JSC Central Design Bureau of Special Radio Materials, which has been specializing in electronic materials science for more than 50 years. The assortment of this enterprise, which is part of the company Roselektronika (Rostec state corporation), includes not only camouflage and protective materials, but also means of protecting information from unauthorized access via an electromagnetic channel. All modern radio-absorbing products developed at the Central Design Bureau of the Republic of Moldova are based on an ultra-wide-range masking material woven using a ferromagnetic microwire in glass insulation.
Briefly about the tactics of using such products. First, of course, the visibility of technology for enemy locators is reduced by an average of 3,5-4 times, which is especially critical for defense against attacking aviation. Secondly, if we assume that all the equipment is covered not only by a camouflage network, but also by air defense systems, it turns out that the enemy, when such on-board radar detects such radio-protected equipment, will already be in the range of the Pantsir-S or Tunguska complexes . In some cases, even an attack using MANPADS becomes possible.
I must say that there is nothing fundamentally new in the camouflage "snow" coating - such solutions have already been used in domestic military developments, but more on that later.
The material is based on the patented in 2006 technology for creating a woven radar absorbing material, consisting of two layers. The aforementioned ferromagnetic microwires are twisted with each other, forming flexible bundles, which, in turn, are woven into the mesh basis of each layer of material. Each such element consists of electrically conductive dipoles located randomly - both along the axis and diverging from it radially in all directions. It is important that the weaving directions are perpendicular to each other in each layer. To fix the two layers with each other, either clips located at certain steps along the entire area of the material, or a fringing along the perimeter of the canvas, are provided.
What happens to the "enemy" electromagnetic waves that hit the domestic radar absorbing material? First of all, microdipoles absorb part of the waves, and part of them repeatedly reflect and re-reflect due to their chaotic arrangement. The material structure itself, recall, a fleecy two-layer, which further contributes to such adventures of radio waves. Ideally, a very small part of the radiation returns to the radar receiver, which, in fact, determines the camouflage effect of the material. On average, less than 1 grams of a ferromagnetic alloy involved in the absorption and reflection of radio waves is required per square meter of such a camouflage blanket.
In the United States, by the way, the most common technology for reducing radar visibility is the weaving of electrically conductive microdipoles of various lengths into a thin layer of non-woven felt. Clothes and camouflage coatings can be made from such a composite, but the level of absorption of electromagnetic energy is noticeably lower than in the Russian know-how. Therefore, it is safe to say that the technology of the “Central Design Bureau of Special Radio Materials” has no analogues abroad. Moreover, in the bowels of the bureau, work is underway to adapt the patented technology to the needs of equipment created according to the stealth concept. It is assumed that the new thin-layer structural fiberglass will contain complex glass fiber with a ferromagnetic microwire. The resulting material will be able to sheathe aircraft, helicopters, sea ships and coast guard boats. Engineers suggest that in comparison with US technology, a domestic novelty will require much less service resources. One only needs to remember how much time it takes to recover from flights of the ultra-expensive coatings B-2 and F-22. However, this is still only the initial theoretical achievements, they are practically not confirmed. At least there is no open information on this subject.
In addition to “soft” radar absorbing materials, the Central Design Bureau of the Republic of Moldova also developed quite “hard” products. So, together with the Moscow Institute of Steel and Alloys, more than 10 years ago a material was obtained on the basis of a macroporous support with nickel particles 10-100 nm in size. The carrier material is TZMK 10, used much earlier as the skin of the Buran spacecraft. An electromagnetic wave incident on such a combined product causes vibrations of nickel microparticles, that is, it is absorbed, passing into thermal energy. The range of absorbed electromagnetic waves is very wide - from 8 to 30 GHz.
On the taste and color of the customer
Camouflage materials developed according to the above technology can be used to protect both stationary objects and military equipment, not at all embarrassing it in functionality: coatings easily take the geometric shape of a camouflage object. In addition to radar protection, such "invisibility cloaks" deform the appearance of the object, then reduce the likelihood of its visual detection. This also contributes a lot to the deforming coloration - a combination of dark green, black and gray-yellow colors in various proportions depending on the area of use.
The immediate predecessors of the new “Arctic” radar absorbing material were the MRPK-1L kit, which was accepted for supply by the Russian Ministry of Defense in 2006. His ancestor was the MRPK, which was adopted by the troops back in 1988 and was a blanket covering an area of 168 square meters. meters. MRPK-1L is slightly larger - 216 square meters. meters. MRPK-1L sets are woven using a nanostructured ferromagnetic microwire in glass insulation, the patent for which was described above. The main method of obtaining this microwire is melting using an inductor in suspension with the formation of a capillary filled with a molten metal. Moreover, it is very important to quickly cool the resulting structure at a speed of more than one million degrees per second. In one technological cycle, you can get up to 10 kilometers of microwire with a total weight of only 10 grams! By the way, the temperature operating range already then ranged from -60 to +60 degrees Celsius. That is, MRPK-1L could initially be used on a snowy background, but there were problems with color. According to this technology, the Central Design Bureau of the Republic of Moldova also developed a suit for the operator of a radioactive explosive device interlock, which reduces the level of electromagnetic radiation incident on it by 1000 times.
What is the difference between the latest Arctic camouflage material from all of the above? First of all, of course, by coloring. In 2019, the Central Design Bureau of the Republic of Moldova together with the YarLi company developed a white pigment masking an object in the optical range of 400–1100 nm. In particular, when developing the pigment, the difficult problem of its adhesion to glass fibers was solved. In addition, the number of layers of material was increased to form a specific reflective signature of the snow cover. Such radar absorbing capes can be used both for the protection of stationary objects and for camouflage of mobile equipment. In the centimeter and millimeter range, the reflection coefficient of the radio wave by the material is 0,5%, and at a wavelength of 30 cm - 2%. In addition, camouflage radio-absorbing coveralls from Nitenol knitwear for a snowy background have already been developed (but have not yet been accepted for supply to the RF Ministry of Defense). These are snow-white warmed suits for snipers, scouts and border guards with a working range of absorbed radio waves from 0,8 to 4 cm.
Naturally, the Central Design Bureau of the Republic of Moldova cannot completely dispense with military orders, especially since the company's products are very specific. Therefore, a significant share in the portfolio of orders has conversion products. For example, these are coatings for anechoic chambers, as well as materials for protecting state and commercial secrets (including special cases for phones). Of great importance are the protective coatings of buildings located near powerful sources of electromagnetic radiation. Finally, the Central Design Bureau of the Republic of Moldova developed a corner reflector, a kind of “anti-masking” product that reflects the radio wave in the strictly opposite direction. It is used in navigation buoys, rescue boats, as well as on the approaches to airfields. But here, too, the military path makes itself felt - the corner reflector is an excellent false target that mimics the radar signature of the protected object.
Recently, everything connected with domestic developments with the prefix “nano” has only evoked a condescending or even irritated smile - the stereotype is too great that they cannot create anything like that in Russia. It turns out that they can, and no Skolkovo and Rusnano are required for this. It is quite close-knit scientific teams formed back in Soviet times.
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