On of the approach to the subject of security is the protection of transmission lines by sensing devices. But in this case protection is limited by detection properties of used sensors. Ideal solution providing completely safe transmission would be a combination of sensing signal with transmitted data. Unfortunately, pulse sensor solutions are not widely used in fiber optic protection. In this paper authors presents solution that can provide higher level of security in data transmission. Team of authors conducted a study on use of pulse interferometer system for transmission line protection and a combination of sensing signal with encoded transmitted data. Analysis of pulse interferometer properties in terms of information security and ability to readout of transmitted data. There is also consideration of using the sensor in areas other than transmission lines protection. Analysis of pulse interferometer properties in terms of information security and ability to readout of transmitted data. There is also consideration of using the sensor in areas other than transmission lines protection.
This paper presents tests of the active composite fence with razor tape module. Due to application of electro-magnetic and optical fiber sensors the fence becomes actively protected. This type of solution may be used to detect violations of peripheral areas . Due to using composite materials the fence is lighter, cheaper and resistant to environmental conditions (including corrosion). What is the most important the composite fence system is transparent to electromagnetic waves. Another advantage of using composite material is the possibility of integration the fiber optic and electro-magnetic cable in the structure of the fence . The durability of a composite is comparable to a standard metal fence. The paper presents test results of the sensors placed on the composite fence. This type of the fence system protection with alarm sensors integrated in its structure is unique in the world scale. Performed tests consisted of laboratory and field tests of modalmetric fiber optic sensor itself, laboratory and field tests of electro-magnetic sensor itself and field tests of both sensors combined. During the laboratory tests an electrodynamic shaker was used to excite the modalmetric sensor to an alarm state. Its excitation distance decreases with the frequency growth. The tests were made for different frequencies and different forces to imitate different fence violation e.g. climbing on it, cutting it or walking along it.
This paper presents possibilities of using the composite fence in the security systems. The fence made entirely of
dielectric materials is neutral for electromagnetic waves. Thus, the fence does not introduce disturbances in propagation
of electromagnetic waves. The use of composite fences reduces reflections of electromagnetic waves which cause
negative effects on fence sensors, microwave barriers and radars. Additionally, the sensing part of the fence sensors can
be integrated in the composite fence structure. Thus, the detecting elements mounted on the fence are invisible for
potential intruder. This paper presents the composite fence with integrated fiber for fiber optic sensors. By arranging the
fiber into fence grid it is possible not only discreet installation of the sensors, but also better transfer movements of the
fence to sensitive optical fiber. By using the fiber as a sensing element the whole fence remain dielectric. Thereby
obtaining a fence entirely transparent to electromagnetic waves which is also monitored for forcing attempts. Another
way to use the dielectric properties of the composite fence is possibility of use electromagnetic sensors. Installation of
the electromagnetic sensor directly on the fence allows to create a monitored zone in the close surroundings on both
sides of the fence. The use of two types of sensors based on different physical phenomena provides an improvement in
the detection properties of the entire security system by reducing the number of false alarms and increasing level of
safety by increasing the probability of detection an attempt to force the fence.
This paper presents a new solution of using the composite fence with a novel fiber optic modalmetric sensor integrated within its structure. The modalmetric sensor is based on changes in a transverse modal field which is generated at the output of a multimode fiber. By a spatial limitation of the transverse modal field observation to its fragment thereof, changes’ transformation in the modal distribution into changes of the output signal amplitude is made. Due to a constant analysis of the structure output signal, detection of an external disorder is possible. Integration of optical fibers with the fence structure allows for an accurate reproduction of the fence movement onto the optical fiber by significantly improving sensitivity of the modalmetric fiber sensor structure.
The rules of quantum physics are now fairly well understood and indisputable. On the basis of these principles are built
safety systems to guarantee unconditional security of data transmission. This is possible due to the random behavior of
the measured photon. Theorems of quantum mechanics are used currently in Quantum Key Distribution systems to
determine the encryption key of cryptographic systems. Sending the single photons through the interferometer it is
possible to determine the probability distribution of a photon detection at a given output depending on the interferometer
imbalance. The use of single photon interference allows reduce the probability of detection of the transmission line
protection. Additionally it provides high safety of transmitted information and minor disturbances. The quantum sensor
can be a device which allows effectively protect transmission lines. In this paper we demonstrate measurement results of
the using single-photon interferometers in security systems and potential capabilities use of such sensors.
In this paper we demonstrate measurement results of the modalmetric fiber optic sensor used for the monitoring of the
fiber optic link integrity to protect it against unauthorized access to classified information. The presented construction
is based on the detection of changes of the modes distribution in a multimode fiber. Any mechanical stress
on the multimode fiber causes changes of polarization and distribution of propagating modes, hence it changes
the distribution of modes at the end of the multimode fiber. Observation of these changes using a narrow core
single-mode fiber allows to use the structure as an optical fiber sensor. We used several kilometers long optical links
to conduct field tests of laboratory sensor. On this basis the prototype module of modalmetric fiber optic sensor
wasbuilt. The modification of optoelectronic part, the variation of sensor length and the change of the method of light
reflection at the end of the fiber enable the use of the modalmetric fiber optic sensor in many applications. The sensor
finds wide range of applications in security systems. It can be applied to protect the museum's collection, transmission
lines and to protect objects of critical infrastructure.
The article describes the technological solution for ship self-defense against pirate attacks. The paper presents the design solutions in the field of direct physical protection. All the solutions are connected with the latest optoelectronic and microwave systems and sensors to detect, recognize and the threat posed by pirates. In particular, tests of effectiveness and the detection-range of technology demonstrator developed by a team of authors were carried out.
Visible, LLTV and anti-fog cameras have different abilities to capture external information, and combining these abilities of the three cameras can greatly improve the environment perception ability of intruders or emergency situations. Designed specifically for professional surveillance use, multi active pixel sensor camera of this type allows targets to be monitored at long distance and tracked using the proportional pan, tilt and zoom system. In the article the research results of the camera to determine realistic and standardized parameters, e.g. range of detection, recognition and identification of humans are described. The paper presents measuring equipment, procedures and results.
This paper presents ways to improve the sensitivity of the interferometric hybrid sensor. Hybrid interferometer is defined as a combination of modalmetric sensor and interferometer sensor. Hybrid interferometer is presented as an application to extensive security systems, where particular importance is the early detection of an intruder. Specification of the hybrid sensor is based on the phenomenon of outputting the interferometer from interference as a result of the disorder. Hybrid sensor sensitivity depends therefore on determine when the sensor leaves the interference. Improve the detection sensitivity can be increased by improving the contrast of interference pattern at the output of the interferometer by using polarization balance. This paper presents a preliminary study and the conclusions of using polarization balance in the hybrid interferometer system.