A new approach to ensuring transport security during the inspection of passengers and personnel.
Babichev Evgeny Anatolyevich
Baru Semyon Efimovich,
Doctor of Technical Sciences, Professor
Porosev Vyacheslav Viktorovich,
Candidate of Physical and Mathematical Sciences,
Ukraintsev Yuri Grigorievich
G. I. Budker Institute of Nuclear Physics SB RAS, Novosibirsk
NEW APPROACH TO ENSURING TRANSPORT SECURITY DURING SCANNING PASSENGERS AND STAFF
Source: Special Equipment magazine
The article is devoted to the topical issue of preventing possible terrorist and sabotage actions on air transport. All over the world, a lot of work is being done to create inspection systems that allow identifying weapons, ammunition, substances and objects that can be used to carry out a terrorist act or hijack an aircraft. The complexity of the problem lies in the fact that inspection systems must combine such contradictory qualities as high accuracy of detecting dangerous objects, short exposure time and a level of dose loads that is safe for the health of passengers.
The paper examines the capabilities of some means of searching for dangerous objects using various physical principles. The characteristics of explosive and narcotic detectors are described in detail, including the latest gas analyzers based on mass spectrometers, contactless passenger personal inspection systems. It is shown that when using modern digital scanning systems, the dose load is hundreds of times less than the natural radiation background. Positive experience of using these systems at airports in terms of detecting substances, materials and products prohibited for carriage by air transport is given.
СThe current international situation does not give any encouraging forecasts that security problems will disappear in the new millennium. Terrorist and criminal threats are a concern and require measures to ensure security at airports. The main objective of pre-flight inspection is the timely prevention and suppression of attempts to board civil aircraft by persons with weapons, ammunition, substances and objects that can be used as a weapon 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).
Various inspection systems are used to solve the problems of screening all employees and visitors at the airport, designed
identify unwanted (from the point of view of flight safety) passengers and their baggage [1]. Currently, there are detailed reviews describing the technical capabilities of means of searching for dangerous objects [2,3]. We will focus only on some. To do this, we will consider the capabilities of various hardware systems for baggage and passenger screening from the point of view of preventing unauthorized persons from entering the controlled area of the airport.
Metal detectors
For pre-flight screening of passengers, aircraft crew members, and civil aviation personnel at airports, the most common screening technologies are stationary and hand-held metal detectors. This type of equipment can detect most types of bladed and firearms, grenades, metal parts of explosive devices, containers with radioactive substances, and other metal objects prohibited from being carried. High-sensitivity metal detectors are used to detect small metal objects on a person's body or in his or her clothing.
The selectivity index of such metal detectors is not assessed, since the search objects and their sizes are comparable or even smaller than personal items. Hand-held metal detectors are used to localize the location of metal objects on the human body after these objects have been detected by a stationary metal detector. With a small flow of people, inspection 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 insensitivity to the following items: weapons made of ceramics and plastics, glass capsules with explosives and narcotics, therefore a mandatory tactile inspection procedure is required.
X-ray baggage inspection systems (introscopes)
Modern high-tech X-ray television scanners for inspection of hand luggage and baggage significantly increase the probability of detecting explosives, using their characteristic features: high density and low atomic number. To detect them, both the registration of the amount of scattered radiation and the difference in absorption at different energies of X-ray radiation are used. Such scanners provide automatic assignment of 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. Technical characteristics ensure high-quality and fast inspection of hand luggage, reliably preventing the transportation of prohibited items and other contraband. The most accurate result is given by specialized computer tomographs, which, like their medical counterparts, reconstruct the object layer by layer based on projection data. Receiving a three-dimensional image of the object at the output, they allow calculating the effective atomic number of the substance in any element of the volume and identifying the presence of explosives. Such devices are used mainly in automated lines of security and control systems.
Television and visual control systems
Search and inspection systems are used to solve problems of video surveillance of the flow of people and cargo and to ensure security on the airport territory. Only a television image can provide information about the situation on the airport territory, about the behavior and individual characteristics of the intruder [4]. 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 with identification of a person by facial features in airport halls to protect against wanted criminals, and the abandoned object detector. Innovative face recognition technology provides a high (at least 80%) probability of face recognition, including when the physical characteristics of the face change: aging, the appearance of a beard and moustache, a change in hairstyle. 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. Border and passport control services of airports, train stations, and immigration services have every reason to use the system for automatic comparison of a photograph on a document with a «live» face.
The system is an effective tool for preventing «unwanted people» from entering a protected area by identifying authorized persons. In the event of registration of a person who does not have access rights to a certain room or area, a specified reaction of the access control system, installed security equipment (blocking doors, turning on a siren), as well as prompt notification of the relevant units will be automatically implemented [5].
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 effectiveness 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 without interference.
This task is solved with the help of the ACS system — this is the unification of inspection and signaling 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. Such systems provide remote control over the airport territory from a single control center. Access identification devices read and decrypt information recorded on identifiers of different types, and also establish the rights of people and transport to move in the protected area.
Places where access control is directly implemented are equipped with a reader, an actuator and other necessary access control means. 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.
Detectors of explosives and narcotics
A modern detector of explosives and narcotics, which is a 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 of the airport and aircraft. The principle of operation of such equipment is as follows: the entering 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 most widely used devices are those that measure the mobility of ions of substances present in the air. However, due to the low pressure of saturated vapors at room temperature, the most effective systems are those that preheat the incoming air to high temperatures and then analyze the gas. This allows for the identification of extremely small amounts of detectable substances hidden on human clothing (Fig. 1). There are new-generation compact gas analyzers that can detect traces of explosives on documents presented for inspection at airports. Unlike other systems of similar purpose, the devices are compact, easy to operate, and can be built into existing terminals at airports and customs offices, as well as in areas with heavy traffic, providing for a quick check of a passenger with the same effect of detecting explosives.
Fig. 1. Portal gas analyzer based on
ion mobility measurement SENTINEL II
Systems that use a different physical principle are gas analyzers based on mass spectrometers. Having initially large dimensions and weight, they have only recently appeared as means of aviation security. However, they have much better sensitivity and accuracy in recognizing hazardous materials (Fig. 2).
Fig. 2. Portal gas analyzer based on mass spectrometry
(photo from http://syagen)
Another detection principle is, for example, the registration of chemiluminescent light of nitrogen oxide. Despite the high probability of false positives due to the fact that many chemical substances can have a similar glow, their simplicity and relative cheapness allow them to be used as a means of initial verification.
Contactless passenger personal inspection systems
The radar scanning portal technology, proposed for use as an additional element of pre-flight screening of air passengers, allows for contactless detection of potentially dangerous items hidden on the human body that are prohibited for carriage by air (Fig. 3). The device emits high-frequency radio waves that do not penetrate human skin, but are reflected from it. In this case, the emitted signal has an extremely low power level. The technological equipment allows for remote control of the screening process from the checkpoint. The verification process, including analysis of the data obtained, requires the intervention of the controller, just as in the mandatory tactile screening procedure.
Fig. 3. ProVision radio wave scanner, previously
sold under the name SafeScout
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 by an image received from the scanner requires extensive experience and training. Nominally, such scanners have a very high throughput. Each scan takes about 2 seconds. However, before entering the inspection cabin, a person must still undress, that is, send shoes, belts and outerwear for inspection through the introscope, which significantly slows down the inspection procedure. Another significant drawback of these systems is the reflection of radio waves from any fabric materials with metallized threads or clothing fabric with a spray of metallized powders (silver, titanium, etc.), which leads to false alarms and reflection from wet (sweaty) clothes.
Suffice it to say that in fashion catalogs you can easily find special underwear for pregnant women with protection from electromagnetic radiation. In the image it is almost impossible to discern anything under the clothes made of such fabric.
Today, digital scanning systems based on X-ray radiation are becoming a fundamentally new means of contactless inspection (Fig. 4). First of all, this concerns ensuring high-quality pre-flight and post-flight inspection at airports and inspection at customs control points at the border. The main problem during inspection is the detection of terrorist weapons and objects made of non-metallic materials and hidden not only under clothing, but also in natural body cavities.
Fig. 4. X-ray inspection system for passengers «SibScan» at the airport
Tolmachevo, Novosibirsk
The X-ray inspection system (XIS) at a safe level of gamma radiation for health allows for the guaranteed detection of swallowed ampoules with drugs, metal and ceramic weapons, and other dangerous objects carried on the body or inside a person. X-ray inspection is well received by both passengers (time saving, delicacy) and airport security personnel (high information content, ease of inspection). Contactless X-ray inspection ensures compliance with the ethical aspects of inspection of certain categories of passengers who, due to religious and other reasons, prefer not to remove their shoes or not to undergo tactile inspection. In addition, the use of a scanner in control areas speeds up the process of passengers going through the inspection procedure.
An important question that constantly arises for both passengers and staff is the amount of radiation exposure, that is, the total effect of human irradiation in terms of long-term consequences during screening. The dose that a person receives during a scan for the IBS is ~ 0.5 μSv [6]. For comparison, the typical dose due to cosmic radiation exposure of a person on a one-way flight from Malaga to London is 10 μSv, from New York to London — 35 μSv, and from Hong Kong to London — 50 μSv. A flight on the Novosibirsk — Moscow — Novosibirsk route creates an effective radiation dose of 23 μSv.
The typical background dose of radiation received by a person from the natural radiation background of the Earth by an average representative of the countries of the European Union per day is 4 μSv. Taking into account that the greatest risk of induction of stochastic effects falls on the gonads and mammary glands, then for this level of radiation it is equal to 0.12 x 10-9 and 0.05 x 10-9 cases, respectively, but its value does not exceed the maximum permissible risk of 1.0 x 10-5 cases for the population. Therefore, the value of radiation risk calculated for an air passenger can be neglected.
According to the sanitary and epidemiological conclusion issued by the Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing (No. 77.99.02.427.D.009838.10.06, Moscow), the effective dose accumulated due to screening on the SRK scanner should not exceed 300 μSv/year for repeatedly screened air passengers, which allows one person to undergo up to 600 screenings per year. With the number of screenings on the SRK no more than 20 times a year, the annual radiation dose will not exceed 10 μSv. Since the radiation to which a person is exposed on the SRK is insignificant against the background of natural radiation, then in accordance with NRB-1999/2009 such radiation can be ignored altogether. Being in the sun or any flight on an airplane makes a contribution to the total human irradiation that is tens or even hundreds of times greater.
To ensure the safety of personnel who are almost constantly near the installation, the presence of an X-ray protection cabin that provides a dose rate of less than 0.1 μSv/hour is a mandatory requirement.
Positive experience of use at airports has shown the high efficiency of the SRK in terms of detecting substances, materials and products prohibited for carriage on air transport that can be used as weapons to attack the crew or passenger. During inspection, there is no need to remove shoes, outerwear, headwear and belt. The image on the monitor can be used to determine the location and identify any objects, including plastic ones. Without resorting to physical contact, the inspector receives a high-resolution image on the screen, allowing the identification of objects of various origins. Personal inspection at the SRK actually gives the inspector the opportunity to «look inside» a person, providing anti-terrorist protection when passing through security checkpoints.
Conclusion
The order of the Ministry of Transport of the Russian Federation of July 25, 2007 No. 104 «On Approval of the Rules for Conducting Pre-Flight and Post-Flight Inspections» put into effect complicates the passage of passengers onto the plane, but creates more security guarantees. However, any changes in the technology of pre-flight inspection of passengers, baggage and personal belongings with them 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 equal to or double the time the passenger spends in the inspection area and waiting for departure in the clean zone. Therefore, in order to resolve the issue of ensuring transport security, it is necessary to carry out timely replacement of technical means of inspection and to apply new technologies when equipping pre-flight passenger and baggage inspection points, which are capable of not only quickly recording threats upon occurrence, but also, more importantly, preventing them.
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