Transport security and modern passenger screening technologies..
Yu. Ukraintsev
Transport security and modern passenger screening technologies
Peace and Security No. 6, 2007
The current international situation does not provide any comforting forecasts that security problems will disappear in the new millennium. Terrorist and criminal threats are a cause for concern and force us to take measures to ensure the safety of citizens.
The main task in air transportation is to provide passengers with a comprehensive security system, which can be divided into two components:
firstly, the inspection of all employees and visitors at the airport, designed to solve the problem of filtering out unwanted (from the point of view of flight safety) passengers and their baggage;
secondly, ensuring the flight according to the route and schedule in full.
To solve the first problem, various inspection systems are used, some of which can even be used to search for drugs and other substances and items prohibited for carriage. The currently existing technical and special means for pre-flight inspection of passengers are divided into the following main classes:
- metal detectors;
- radiation monitoring devices;
- television and visual monitoring systems;
- explosive and narcotic detectors;
- X-ray systems for baggage inspection (introscopes) and passengers.
Flight safety must be paid for, but the passenger's willingness to pay more for a ticket will depend on the overall safety of the flight, which will protect him from malicious intent and technical reasons (including the «human factor»). Which of these should be paid more for is still a question. With the limited financial resources of the air carrier, the distribution of this quota is a serious issue. The complete safety of the passenger is determined by the absence of a terrorist on board, and the technical condition of the aircraft, and the qualifications of the crew. Let us immediately stipulate that airport security is threatened not only by terrorism. The arsenal of offenders includes smuggling, attempts to illegally cross the border, theft, etc.
Based on a review of scientific, technical and patent literature, we will try to understand the main characteristics of various systems for conducting pre-flight and post-flight inspections at the airport and evaluate a suitable model. To do this, we will consider the capabilities of various hardware for baggage and passenger inspection systems from the point of view of ensuring terrorist security. The equipment inside each of the listed classes of devices differs in operating principles and design. The most modern achievements of science and technology are used in the development of inspection systems. All hardware is made on the basis of modern technologies and design, they use advanced components, and all products are certified in Russia. In terms of their characteristics, Russian developments are not inferior to Western counterparts, and in terms of the «price — quality — functionality» criterion, they are significantly superior. However, when choosing a particular inspection system, the decisive factor is not the operating principle embedded in it, but the extent to which this system meets the following requirements:
- guaranteed detection of items and substances prohibited for carriage;
- causing minimal possible damage to the controlled object;
- absence of false alarms caused by personal items;
- absence of false alarms caused by external interference of various natures;
- reliability of equipment;
- high throughput.
Metal detectors
For pre-flight inspection of passengers, aircraft crew members, and civil aviation personnel at airports, the most common inspection technologies are stationary and hand-held metal detectors. This type of equipment can detect most types of bladed weapons and firearms, grenades, metal parts of explosive devices, containers with radioactive substances, and other metal objects prohibited for carriage. Stationary metal detectors have different antenna designs (panels, columns), and a harmonic or pulsed type of magnetizing field. Thus, to ensure the homogeneity of the field in the passage zone and to increase selectivity (the ability to distinguish weapons from personal items), many modern metal detectors use systems of several transmitting and receiving coils. Stationary models are manufactured with different sensitivities. Standard sensitivity metal detectors are used primarily to search for weapons and ideally should not react to personal items, i.e. they should have good selectivity. High sensitivity metal detectors are used to detect small metal objects on the human body or in his clothes. The selectivity index of such metal detectors is not assessed, since the sizes of the search objects are comparable or even smaller than those of personal items. Hand-held metal detectors are used to localize the location of metal objects on the body of a person who has been searched after these objects have been detected by a stationary metal detector. With a small flow of people, the search can only be carried out using a hand-held metal detector, but in this case the probability of detecting prohibited items is significantly reduced. The main disadvantage of metal detectors is their insensitivity to the following items: weapons made of ceramics and plastics, glass capsules with explosives and narcotics, therefore a mandatory tactile search procedure is required.
Radiation monitoring devices
One of the important and effective elements in the complex of measures to ensure transport security is continuous radiation monitoring to prevent unauthorized movement of nuclear materials through checkpoints. Nuclear materials are identified by their gamma and neutron radiation. Pedestrian radiation monitors are used together with metal detectors, since only in this case can one prevent the carrying of radioactive substances placed in a protective metal container that absorbs gamma radiation, therefore, inspection, including of things carried by passengers, at airports is carried out in two stages. At the first stage, a search is made for metal objects prohibited for carrying, and then the person is checked for the presence of nuclear materials. The «Spectr» device is the only unique domestic combined inspection device that combines the functions of a metal detector and a radiation monitor. It is designed as a U-shaped portal, in the side posts of which are placed sensitive elements of the metal detector and ionizing radiation detectors, which are capable of recording even the most insignificant traces of nuclear materials. Control is carried out in the free passage mode without stopping people in the control zone. Passengers who arouse suspicion when passing will be additionally checked by an inspection inspector. However, after the installation of this equipment, much fewer people will be subject to manual palpation.
Television and visual control systems
Search and inspection video surveillance systems are designed to solve a wide range of security problems, primarily to control the flow of people and cargo through the airport. Only a television image can provide information about the situation on the airport territory, about the behavior and individual characteristics of the intruder. Covert surveillance allows the operator to visually monitor the situation, see how the intruder entered the airport territory or the terminal building, and track his actions. Particularly noteworthy are the modules for capturing faces to identify a person by facial features in airport halls to protect against wanted criminals, and the detector of abandoned objects. The appeal of this method is based on the fact that it is closest to how we identify each other.
A television camera is the “eyes” of a security television system. Its choice determines what the operator will see on the video monitor screen. The most effective solution from a technical and economic point of view is to organize control based on digital video surveillance systems using digital channels for transmitting video images. For video channels transmitting images of especially important areas with controlled access and airport areas where there should be no human movement at all or for a certain period of time, it is recommended to use motion detectors. The human factor at inspection and control points can be eliminated by such a mechanism of the video system operation, in which all actions of the operator and video surveillance systems are recorded. Recording of the situation, i.e. recording of information, is carried out continuously or according to a schedule. It is carried out on special S-VHS standard video recorders or using digital recording devices with a resolution of at least 400 television lines. The digital video archive is not subject to aging, the digitized video image can be transmitted over almost any distance without loss of quality. When monitoring the situation on the airport territory, at least two video monitors must be installed at the control points to display the current situation at the facility and to display alarm events. The devices of the control systems are programmed in such a way that when any security sensor associated with any television camera is triggered, its image is immediately displayed on the screen of an additional «alarm» video monitor.
Access control and management systems and means (ACMS)
Digital video surveillance systems are usually integrated with access control and management systems. This allows recording all those entering in a separate archive. Modern systems for monitoring the movements of not only passengers, but also the entire contingent of citizens arriving at the airport, increase the efficiency of detection systems. At the same time, employees with the necessary authority should feel free during working hours and be able to move around the building or territory of the airport terminal without interference. This problem is solved with the help of the ACS system — this is the unification of inspection and alarm systems, access control and management equipment, external and internal video surveillance systems into a single complex of technical means of physical protection of the airport and the adjacent territory. And also providing remote control of the state of these systems from a single control center.
The video surveillance system frees security personnel from routine identification work, giving them additional time to perform basic functions of protecting the territory and protecting employees and passengers from criminal attacks.
The following composition of the ACS system is recommended for protecting especially important airport facilities:
- access identification devices (identifiers and readers);
- access control and management devices (controllers);
- central control device of the ACS system (computer);
- executive devices of the system, installed at the entrances to closed areas and to important premises.
Access identification devices read and decrypt information recorded on identifiers of different types, and also establish the rights of people and vehicles to move in a protected area. Places where access control is directly carried out are equipped with a reader, an actuator and other necessary access control means.
An identifier is an object on which code information is entered using special technology, confirming the authority of its owner, which is used to control access to a protected area.
A reader is an electronic device designed to read code information from an identifier and convert it into a standard format transmitted to the controller for analysis and decision-making. The latest models (biometric) of the reader, in which identification is carried out according to the individual physical characteristics of the owner, almost completely eliminate the possibility of unauthorized access to the sterile zone. Such compact devices, using advanced technologies to perform tasks to prevent terrorism and ensure the security of premises with controlled access, are supplied by many Russian companies.
Detectors of explosives and narcotics
A modern explosive and drug detector, which is a second-generation gas analyzer, allows detecting microscopic particles of explosives hidden on the body of a person passing through the detector. This system complements metal detectors, ensuring maximum security for airports and aircraft. The operating principle of such equipment is as follows: an incoming passenger is blown with air streams, which then enter the test section of the device, and after a few seconds the results of the analysis for the presence of particles of explosives (hexogen, ammonium nitrate, trinitrotoluene, dynamite, etc.) are displayed on the monitor. The device operates on the technology of ion mobility spectrometry, which allows identifying ultra-small quantities of detectable substances hidden on the human body. Then, security personnel only need to perform an additional check of the «suspicious» passenger. This equipment can be configured to work with new types of hazardous substances by replacing the program code, which significantly expands its functionality and increases its service life.
A simpler Russian gas analyzer of the new generation allows to detect traces of explosives on documents presented for inspection at airports. The device is based on advanced technology, which is based on the principle of nonlinear dependence of ion mobility on electric field strength. This technology made it possible to create a particularly sensitive device capable of detecting the presence of explosive vapors in real time at their concentration in the air of about 10-13 g/cm3. The detector does not require a special gas carrier or preliminary calibration. Unlike other systems of similar purpose, the device is compact, easy to operate, can be built into existing terminals at airports and customs, as well as in areas with heavy traffic, providing a quick check of passengers with the same effect of detecting explosives.
X-ray baggage inspection systems (introscopes)
The main objective of pre-flight inspection is the timely prevention and suppression of attempts to board civil aircraft by persons carrying weapons, ammunition, substances and objects that can be used as weapons to attack the crew and passengers of these aircraft with the purpose of capturing (hijacking) them or that can cause an emergency. (Order of the Ministry of Transport of Russia dated November 21, 1995, No. 102). This task is well solved by modern high-tech X-ray television scanners for inspection of hand luggage and baggage. The digital X-ray dual-energy scanner automatically assigns colors to materials with different atomic masses, which allows the operator to easily identify objects inside the baggage. These devices reliably detect explosives, ceramic and organic objects. The technical characteristics ensure high-quality and fast inspection of hand luggage, reliably preventing the transportation of prohibited items and other contraband. Excellent image quality and a wide range of functions allow you to quickly identify explosive devices, any metal and non-metal weapons, drugs, since these objects are painted in different colors. The installation can be used in automated lines of security and control systems.
Passenger personal inspection systems
The personal inspection system must cope with a large passenger flow. Probably everyone has encountered long, annoying queues in the inspection area, which, due to increased security requirements, risk simply paralyzing the work of the airport. The radar scanning portal technology, proposed for use as an additional element of pre-flight inspection of air passengers, allows for contactless detection of potentially dangerous items hidden on the human body that are prohibited for transportation by air. The operating principle of the system in the terahertz range of the electromagnetic spectrum is based on holography and ensures the detection of objects made of metal, wood, ceramics, plastic and other materials hidden on the human body. At the same time, the emitted signal has an extremely low power level and is absolutely harmless, and active millimeter waves, without penetrating the human skin, are reflected from it. The system of each scanner includes: an inspection chamber — two rotating antenna arrays, which are sources and receivers of radio frequency signals, control electronics and a computer for signal processing. An important feature of the scanner is its high throughput. Each scan takes about 2 seconds. The technological equipment of the equipment allows for remote control of the inspection process from the checkpoint. The inspection process, including the analysis of the data received, requires the intervention of the controller, as well as during the mandatory tactile inspection procedure. This device does not detect objects in the natural cavities of a person and inside him. When using the device in the pre-flight inspection of a passenger, professional training of personnel is necessary, since the ability to identify an object from an image obtained from the scanner requires extensive experience and training. It is almost impossible to distinguish anything on the monitor from an image under a wet handkerchief or sweaty shirt.
Screenshots from the display of the SibScan SRK. The hidden plastic knife and pistol model (4 mm thick fiberglass) are clearly visible. Two pictures show a piece of soap simulating explosives. Dose — 1 μSv (equivalent to the dose from natural background for 10 minutes of flight).
At present, there are no similar developments of contactless inspection systems with the technical characteristics of the SRK, where the resolution is 1×1 mm and the effective radiation dose of an air passenger is less than 0.5 μSv, a 2000×800 mm image in 5 s.
Systems of similar purpose in comparison with the SRK:
Scannex (South Africa) — 3 times higher radiation dose. Twice as long scanning time. Higher price ($500 thousand).
Conpass (Belarus) — 3 times higher radiation dose. No protection of others from scattered radiation. Less convenient design with transportation of the person being examined. 2.5 times longer scanning time. High price ($250 thousand).
Secure 1000 (USA) — a person is not scanned, but rather «felt» by a narrow «pencil» beam, first from the front, then from behind. Spatial resolution is 10 times worse. Scanning time is 3 times longer, since it is necessary to make a «circle» turn in the middle of the examination procedure. Objects swallowed or hidden in natural body cavities are not visible. It is unclear how to search for something under thick clothing or in shoes. Price — $110,000.
Homo-Scan — scanning field size 2000×800 mm. Detector scintillator + photodiodes, spatial resolution 3.8×3.8 mm, radiation dose 1 μSv. Scanning time 5 s. Very large geometric distortions vertically, especially in the upper part of the body. Objects hidden in shoes are poorly visible.
From the above, it can be stated that the SRK is the most effective and safe for human health means of timely detection, prevention and suppression of attempts to penetrate strategically important objects and transport of persons with weapons, ammunition, flammable substances, toxic, radioactive and other dangerous objects and substances.
Conclusion
The implementation of the order of the Ministry of Transport of the Russian Federation dated July 25, 2007 N 104 «On Approval of the Rules for Conducting Pre-Flight and Post-Flight Inspections» will complicate the passage of passengers on board the aircraft, but there will be more security guarantees. However, any changes in the technology of pre-flight inspection of passengers, baggage and items carried by passengers should not increase the duration of servicing departing passengers and affect their comfort. As an object of service, a passenger must spend a minimum amount of time to go through all the sequential operations technologically necessary for boarding an aircraft. Flight time should not be comparable or double the time the passenger spends in the inspection area and waiting for departure in the clean zone. Therefore, when addressing the issue of transport security and preventing terrorist or criminal threats, it is necessary to promptly replace technical inspection equipment and apply new technologies when equipping pre-flight inspection points for passengers and baggage, which are capable of not only quickly recording threats in fact, but also, more importantly, preventing them.
About the author: Yu. Ukraintsev, senior research fellow, I. Budker Institute of Nuclear Physics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk
Source: «Peace and Security» journal