Experience of using the nr900EK “Korshun” non-linear radar to search for explosive devices..
KALABUKHOV Viktor Anatolyevich,
SHCHERBAKOV Grigory Nikolaevich, Doctor of Technical Sciences, Professor
EXPERIENCE OF USING THE NR 900EK “KORSHUN” NON-LINEAR RADAR FOR SEARCHING FOR EXPLOSIVE DEVICES
Introduction
Currently, the problem of countering terrorist attacks using explosive devices (ED) has become especially relevant. Illegal armed formations and terrorist groups, both in the Russian Federation and in other countries, widely use ED to carry out attacks on military and civilian targets.
Work on searching for, rendering harmless or destroying engineer mines, artillery ammunition, sabotage and terrorist means, improvised explosive devices and other explosive objects on the territory of the Russian Federation is carried out by demining units of the Ministry of Defense, the Ministry of Internal Affairs, the Federal Security Service and the Ministry of Emergency Situations.
The article summarizes the practical experience of the portable nonlinear radar NR 900EK “Korshun”, designed for remote detection of controlled explosive devices, which has proven itself well in the course of performing tasks on searching for and defusing explosive objects.
History of creation
In the early 80s, during military operations in Afghanistan, Soviet troops first encountered the use of homemade explosive devices (land mines) controlled by radio by the mujahideen.
The study and technical analysis of the remains of explosive devices found at the explosion site, and subsequently of whole samples that for some reason did not explode, showed that the explosive devices were activated using special industrial-grade remote explosion control equipment.
Radio-controlled explosive devices, unlike conventional mines, were installed on the side of the road, several meters from the side of the road, or on mountain slopes adjacent to the roads. It is clear that explosive devices installed in this way could not be detected by mine detectors and service dogs.
Thus, by the mid-80s, the troops began to experience an acute need for a means that would provide remote search and detection of radio-controlled explosive devices. The problem became serious, and the efforts of scientists and designers were aimed at finding ways to solve it. It was then that they remembered about non-linear locators, which at that time were already widely used by the operational and technical services of the former KGB of the USSR to detect hidden electronic devices for unauthorized acquisition of information.
In a relatively short time, based on the existing scientific and technical groundwork, a portable military device “Orthopedist” was developed, manufactured and tested, based on the method of nonlinear radar. The device had a powerful pulse transmitter, a receiving and emitting antenna with a circular directional pattern and a single-channel receiver operating on the 2nd harmonic of the probing signal. The pilot military operation of the Orthoped devices conducted in Afghanistan demonstrated their high efficiency in detecting radio-controlled explosive devices, but at the same time revealed a number of design and operational shortcomings that required the device to be improved.
The new nonlinear locator (photo 1), developed based on the results of the military operation of the Orthoped devices and called the INM non-contact mine detector, was adopted by the Soviet Army in 1988 and remains in service to this day.
The main purpose of the INM seeker is to search for mines equipped with non-contact fuses, as well as executive devices of radio blast control devices. The disadvantages of the device include its significant weight (12.5 kg), short continuous operation time (no more than 2 hours), lack of selection of nonlinear transitions by the 3rd harmonic, which is necessary for effective operation in conditions of littered terrain with metal debris, and a relatively high power of emitted pulses (500 W).
In the mid-1990s, work began on upgrading the INM seeker. However, the economic crisis that began in the country, which led to the decline of the defense industry and science, did not allow for a deep modernization of the device, and it was reduced to a reduction in its weight and dimensions. The search characteristics of the upgraded INM-M seeker remained the same as those of its predecessor. In early 2002, it was adopted to replace the INM.
After Afghanistan, INM seekers were used in Abkhazia and Chechnya. However, the conditions for performing tasks by sapper units in these regions were significantly different from those in Afghanistan, in particular, the background and target situation turned out to be much more difficult here.
It was the experience of the counter-terrorist operation in the Chechen Republic that fully highlighted the fact that the existing military means of searching for mines and explosive devices no longer meet modern requirements. It can be said without exaggeration that INM and INM-M seekers were never used there due to their low efficiency.
Meanwhile, the scale of the use of VU by illegal armed groups against federal forces continued to grow and by 2001 had grown so much that it gave rise to talk about the beginning of a “mine war”, although actual engineer mines were rarely used by militants. Mining in Chechnya soon turned into a type of profitable activity, in which the local population, including children, was involved.
The technical level of radio detonators used by militants increased significantly.
In an attempt to find a replacement for the ineffective NM seeker, military experts conducted a review of the domestic market for commercial search equipment. As a result of this analysis, the portable pulse detector of nonlinear transitions NR 900EM, developed and mass-produced by the Moscow-based ZAO “YUTTA Protection Group”, was selected for further testing in the field.
After preliminary evaluation tests of the NR 900EM device at one of the military training grounds near Moscow, specialists from the Ministry of Defense conducted its experimental military operation in the fall of 2001 at the base of the Joint Group of Troops (Forces) in the Chechen Republic.
The experimental military operation of the NR 900EM device allowed us to formulate the tactical and technical requirements for a new promising non-contact mine detector, but work on its creation never began. The reason is banal and was that at that time the modernized INM-M detector was being prepared for adoption, and setting up new experimental design work would mean admitting the fact that the device being adopted for service was essentially no better than its predecessor.
As an alternative solution, the Ministry of Defense proposed that ZAO Zashchity Group-UTTA independently modify the NR 900EM non-linear radar, taking the results of its experimental military operation as a basis.
It's unbelievable, but true. In just three months, the company developed the design of a new device on its own initiative and manufactured pilot samples. It is unlikely that in the history of domestic instrument-making, especially in its recent years, there are enough examples of such scientific, technical, technological and production mobility of an enterprise.
This is how the nonlinear radar NR 900EK, the famous “Korshun” (photo 1)
Photo 1. Detector of nonlinear
transitions NR 900 EK “Korshun”
Capabilities of the NR 900EK “Korshun”
The NR 900EK “Korshun” non-linear radar is a portable device designed to search for controlled explosive devices and other technical equipment containing semiconductor components, regardless of their functional state, i.e. whether they are in the on or off state.
According to the experts who have worked with it directly, the device has high search characteristics, selectivity and noise immunity, is easy to use, and its design and weight and size parameters ensure high-speed search. It should be noted that this is the only commercial model in Russia developed specifically for engineering reconnaissance tasks.
Table. Technical characteristics of the NR 900EK “Korshun” radar
| Type of probing signal | Pulse |
| Transmitter power | 180 W |
| Power control range | Minimum 30 W Maximum 180 W |
| Receiver type | Two-channel (2nd and 3rd harmonics) |
| Receiver sensitivity | -130 dB/W (adjustable) |
| Sensitivity adjustment range | 0; -10; -20; — 30 dB |
| Supply voltage | 6 V |
| Power source | Acid battery |
| Continuous operation time | 10 hours |
| Operation indication | Headphones, 2 LED strips |
| Range of operating temperatures | -30…+50° C |
| Weight of the equipped device | 3.5 kg |
It is important that when creating the “Korshun”, its developers tried to take into account the requirements of military standards in terms of climatic performance, mechanical strength and resistance to external influences (vibration, rain, snow, dust, etc.), transportability and ergonomics.
Structurally, the device consists of an antenna system, a transmitter and two receivers. Switching between operating modes is carried out using a control panel located on the handle of the antenna system. The transceiver unit is placed in the unloading vest, and only a small antenna remains in the hands, which significantly facilitates the operator's work (photo 2).
Photo 2. Placement of the NR 900EK radar on the operator
A distinctive feature of the NR 900EK radar is its high noise immunity and the ability to select semiconductor and corrosion nonlinear junctions. This ensures the ability to work effectively in conditions of high contamination of the terrain with metal debris. Due to such selectivity, the search rate for explosive devices increases significantly.
During the tests, “Korshun” demonstrated brilliant capabilities in detecting explosive devices located behind a chain-link fence, behind barbed wire, in culverts, under metal hatches, as well as high spatial selectivity. It should be noted that in such conditions, no metal detector could detect the “bookmark”.
Due to its selectivity, it is possible to use the NR 900EK radar to check controlled sections of the railway track and rolling stock. During the tests conducted by the Russian Railway Troops, the possibility of detecting controlled VUs was verified in various installation options on railway tracks: at the intersection of a rail and a sleeper, in a sleeper box, under the rails between sleepers, in a wheel pair of rolling stock and some others (photo 3).
Photo 3. Checking the railway track with the NR 900EK radar
In April 2002, the NR 900EK radar was successfully tested to determine the possibility of its use by engineering units of the Main Internal Affairs Directorate of Moscow in the conditions of Moscow metro stations.
Baptism of Fire
The first experience of combat use of the Korshun radar was gained by the Internal Troops of the Ministry of Internal Affairs of Russia, which in 2002 equipped one of its engineering units with these devices, which carried out a task as part of a group of troops in the North Caucasus.
The practical use of the device was preceded by training and operator training, in which specialists from ZAO “Zashchitsa Group – UTTA” participated.
In the first month, two radio-controlled landmines were detected using the Korshun radar, installed in one case behind a brick fence, in the other – behind a reinforced concrete fence. In just 6 months, engineering reconnaissance patrols equipped with Korshun devices detected and neutralized 15 radio-controlled landmines of varying power. It should be especially noted that there were no explosions on the routes checked using the Korshun radar. The detection capabilities of the Korshun radar are clearly illustrated by the real detection schemes presented in Fig. 1, 2, 3.
Fig. 1. Detection of a tripwire mine
Fig. 2. Detection of a “bookmark” in urban conditions
Fig. 3. Detection of a “landmine” under the road surface
Despite the fact that the NR 900EK device is, first and foremost, a search tool, it can also be used to examine objects suspected of containing explosive devices: abandoned briefcases, bags, boxes, packages, etc.
Good results were obtained during the use of the Korshun by a group of the engineering and technical department of the St. Petersburg OMON in 2002 during special operations and searches, when it was used to detect homemade radio-controlled explosive devices.
Experience using the NR 900EK radar has shown that it can be effectively used to solve the following tasks:
- checking controlled sections of roads and railway tracks for the presence of controlled explosive devices;
- checking buildings and premises for the presence of explosive devices controlled by radio or equipped with electronic time-delay devices, as well as detecting devices for illegal data collection and unauthorized means of communication (cell phones) in prisons and pre-trial detention centers;
- detection of hidden caches (warehouses) with weapons and ammunition, means of communication, explosion control equipment;
- inspection of citizens, vehicles and cargo.
It should be noted that in terms of its search characteristics, noise immunity and selectivity, the NR 900EK “Korshun” radar surpasses other domestically produced non-linear radars and is several times more effective than foreign analogues.
Prospects of the NR 900EK “Korshun”
Despite the positive experience of operating and using the NR 900 EK radar, equipping troops with it is extremely slow.
Currently, only the Internal Troops of the Ministry of Internal Affairs, railway troops and units of the special services of Russia have acquired small batches of devices (single pieces).
The Engineering Troops of the Ministry of Defense have not yet acquired a single Korshun”, although the fight against illegal armed formations in the North Caucasus continues, and these radars are needed by regular army sappers, paratroopers and special forces.
In the summer of 2003, on the instructions of the Security Council, the Ministry of Defense conducted interdepartmental comparative tests of existing nonlinear radars, with the aim of analyzing their tactical and technical characteristics and efficiency in detecting explosive devices. And again, Korshun demonstrated the best search and ergonomic characteristics among the devices submitted for testing. And once again, no specific decisions were made.
While the Ministry of Defense is deciding what to do with Korshun, interest in this device is growing from countries near and far abroad. The device has already been supplied to anti-terrorist units in countries such as Israel, Germany, England, and the USA.
It turns out that we are arming the entire world with modern technology, while our own army will use what we have… If only we wouldn't have to buy this same NR 900EK abroad later – under a different brand name and with instructions in a foreign language.
Literature
1. Ed. V.A. Zarenkov “Explosive Objects. Methods and Means of Search, Detection, Neutralization, and Disposal” – St. Petersburg, 2002.
2. Detector of nonlinear transitions NR-900EK “Korshun”. TO and RE.
