FIBER-OPTIC PERIMETER DETECTION SYSTEMS OF THE VORON SERIES.

In the new 2011, the editors plan to continue publishing scientific and practical materials devoted to perimeter fiber-optic detection devices, which have been developed and mass-produced for ten years in “Applied Radiophysics” under the VORONTM trademark. The first of this series of articles was published in issue 2/2010 and contained a general overview of the VORONTM perimeter detection devices. In this and subsequent publications, interested readers will receive more detailed information about the design of the VORONTM systems and the features of their installation and commissioning.
                                                       Instead of an Introduction
Recently, interest in perimeter fiber-optic security systems for extended facilities and territories has sharply increased again. In magazine publications and commercial proposals, various ideas, options and schemes for constructing long-range fiber-optic security systems are discussed and proposed, including those with localization of the impact point with an accuracy of up to a few meters. In this article, we will not subject these often semi-fantastic proposals to scientific and technical analysis, in most of which the effect obtained in the laboratory and the apparent obviousness of the possible application are passed off as a completed technical implementation at the system level. Long-timers of the perimeter systems market will probably remember that in the early 90s, something similar happened in the last century, when the components of fiber-optic systems that came to Russia and became available made it easy to verify the sensor capabilities of then multimode optical fiber for building security devices, and the emerging market relations, in turn, allowed the newly minted businessmen to quickly «cobble together» and «sell» primitive perimeter security devices. According to the author, at least 7 organizations were noticed in «fiber-optic sins», including very large market players. At the same time, no one, with a few exceptions, bothered to conduct full-scale research work and understand that fiber-optic distributed sensor systems have fundamental physical differences from electrical cable systems, giving rise to numerous problems during actual operation. As a result, after 2-3 years, Customers, having had their fill of the delights of these «raw» semi-handicraft products (sometimes, false alarms exceeded several hundred per day!!!), at the mention of fiber-optic security systems, burst out with well-known «winged» expressions. Thus, a very promising direction in perimeter security technology was almost destroyed as a result of the actions of incompetent businessmen. The danger of a repeat of such a scenario exists today.
       In fact, even now there are very few companies in the world that produce reliable serial fiber-optic perimeter security systems. Among them, the only one in Russia left over from those “dashing” 90s is “Applied Radiophysics”, whose team, with its high scientific potential (75% of the team are candidates and doctors of physical and mathematical sciences) with the help of many years of field research, physical experiments and tests in various climatic conditions, not only successfully overcame childhood diseases of fiber-optic perimeter security systems, but also, having received a number of breakthrough solutions, including in the field of artificial intelligence, has been developing and producing fiber-optic perimeter security systems under the “VORONTM” trademark for more than 10 years.
                       
                       Basic principles of constructing VORONTM series systems
                                                 Linear parts of the VORONTM complex
The VORONTM perimeter detection systems are designed to create extended multi-zone and multi-line perimeter detection systems (PDS) based on fiber-optic distributed sensors of mechanical impacts on deformable barriers of various types. Any version of the VORONTM complex consists of a control panel or hardware and software part and a linear part.
Linear detection units of all modifications of the VORON series perimeter detection systems contain only passive, maintenance-free, non-electric elements (Fig. 1). The main element of the linear detection units of the VORONTM systems is the fiber-optic sensor cable of the V-KDVOT series (PRAG.411425.075TU). It is in the optical fiber of the sensor cable that the polarization-phase characteristics of light radiation change under mechanical influences, causing even slight bending deformations of the sensor cable. The sensor cable (Fig. 2) is a steel cable coated with a special type of polyethylene with a polycarbonate module containing optical fibers placed inside the cable. The outer diameter of the cable does not exceed 8 mm, the tensile strength reaches almost 1 ton. The service life of such a sensor cable is at least 25 years! (Compare with sensor cables based on copper wires using the triboelectric effect, which require replacement every 5-7 years!!) 
Depending on the security tasks to be solved and, accordingly, the optical circuits used, implementing certain physical principles of converting mechanical effects into changes (modulations) of the polarization-phase characteristics of radiation propagating through optical fibers, VORONTM complexes can use both multimode and single-mode modes of radiation propagation in optical fibers.
However, this information is absolutely unimportant to the real consumer. What is important to him is that there is only a sensitive cable, which is sufficiently resistant to natural influences (at sites near Moscow in the period of December-January 2010-2011, during the notorious freezing rains, up to 3 trees fell almost simultaneously in some security areas, completely damaging the fence, but the V-KDVOT sensor cable remained fully operational!!). This sensor cable is rigidly fixed to the fence, implementing the options of 1 pass or 2 passes of cable lines (Fig. 3), thereby turning the fence into a vibration-type signal fence. Another pass of this same sensor cable under the fence at a depth of 30-40 cm can automatically supplement the fence with an anti-undermining device.
For those who care about design issues, we will add that the sensor cable is attached to the mesh fence with special clamps — ties at the rate of 4 attachment points per 1 linear meter. The lower cable line is attached at a height of 35-40 cm from the ground surface. The upper line of the sensor cable is located at 2/3 of the height of the fence, and when using a canopy or a spiral such as AKL, the sensor cable is attached to these elements. Installation of the sensor cable, as well as any cable products with a polyethylene coating, must be carried out at temperatures not lower than (-100C). But operating temperatures (not to mention storage temperatures) can reach -650C in winter and + 850C in summer.The length of one address section or security zone in VORONTM systems is determined by a number of different factors, mainly related to the response time of personnel to a signal about a possible intrusion, as well as the presence or absence of video surveillance systems. In most cases, the European standard is used: the length of the security zone is 200m-300m. The maximum distance of the protected zone from the photoreceiver of the hardware can reach 60 km.
So, the V-KDVOT sensor cable is mounted on the fence in accordance with all the Manufacturer's recommendations. Next, it is necessary to connect optical radiation to one of the ends of the sensor cable and transmit changes in the polarization-phase characteristics of this radiation, which occurred when affecting the signal fence, to the information processing center. For these purposes, a standard fiber-optic multi-core armored single-mode cable produced by a large number of domestic cable plants is used. This cable is designed for the construction of optical communication lines and is usually buried in the ground to a depth of 40-70 cm. The VORONTM system communication cable contains as many optical cores or light guides as there are security zones or areas planned to be organized at the facility. If it is planned to use video surveillance at the same facility, then it is possible to provide for the redundancy of additional optical cores in the same cable. The communication cable starts at the rack with the optoelectronic equipment of the VORONTM complex and runs in the ground at a distance of several meters from the fence line inside the protected area along the entire perimeter.
To connect the sensor cable to the communication cable, a standard feed-through sealed joint used in the construction of optical communication lines is used. However, unlike the communication lines in the VORONTM complex, this joint contains a passive optical converter of the V-AFFA series, which is designed to convert the polarization-phase modulation of radiation in the V-KDVOT sensor cable into amplitude modulation of radiation in the optical communication cable, independently on 2 address zones. Depending on the type of deformation properties of the fence and, accordingly, the modification of the V-KDVOT sensor cable, the V-AFFA series converters have different designs and, accordingly, different designations. For example, V-AFFA-1-2 (Fig. 4) is intended for placing the sensor cable on fences of the SSCP, PKLZ, AKL, Makhaon type, and the V-AFFA-2-2 converter is used in case of installing the sensor cable on rigid forged (or from a profile pipe) and concrete fences. So, all the main elements of the linear part of the VORONTM complex are presented. The further procedure for installing the linear part of the VORONTM complex is as follows:
1. The communication cable at the border of each 2 security zones is cut using a standard set of tools for a communication line installer. One optical fiber is allocated, determined for a given security zone.
2. In the optical joint, all other optical modules and fibers are placed in a standard splice cassette, which follow in transit to the next joint. (Fig. 5)
3. The selected fiber is cut and its ends, after standard stripping, through the AFFA converter, are connected using optical welding on a standard welding machine, with the ends of the optical fiber of the sensor cable.
4. With a two-pass placement of the sensor cable on the fence web in the same optical joint, a similar operation is carried out for the adjacent security zone.
After checking (translucent) the integrity of the optical path, the couplings are sealed in the standard manner, and then, together with the communication cable, they are immersed in the ground and ……they are forgotten for at least 20-25 years. Only a modest and inconspicuous optical cable sensor remains on the fence.
All these not too complicated and standard operations for installers of optical communication lines during installation of VORONTM complexes are carried out by specialists whose level of training allows them to receive a Manufacturer's Certificate for the right to install and commission VORONTM complexes.
That's all there is to the installation. And there are no cabinets with power supply on the perimeter, no cabinets with controllers, no problems with their heating and, accordingly, with paying for ever more expensive electricity. In general, there are no more problems on the perimeter. But there is a signal vibration barrier of the most modern type, which…… is maintenance-free!
ATTENTION!
Counterfeits of our VORON™ series products have appeared on the market. In this regard, we inform you of the following:
«APPLIED RADIOPHYSICS» has exclusive rights to develop, manufacture and supply products under the VORON™ trademark.
If you or your colleagues are offered a VORON product that has a name that completely coincides with our product, or a «modified version of VORON-2M-S-RH», or components with decimal numbers «CHARM» or other versions of VORON products manufactured NOT BY «APPLIED RADIOPHYSICS», then this is definitely a counterfeit product.
Beware of fakes!