Skip to main content

Currently Skimming:

4 System Concepts
Pages 41-52

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.


From page 41...
... In a field application, resolution and contrast might be sacrificed for the ability to gather information when the subject is farther than a few meters away from the screener. In this report, the committee focuses mainly on the screening of people in a controlled area such as an airport using a portal system, but it should be kept in mind that 41
From page 42...
... The most likely fielding of millimeter-wavelength/terahertz imaging systems will be accomplished as a part of an overall systems approach as an element of the passenger-screening checkpoint and baggage checkpoint, or as part of the access control to the secure areas of the facility or aircraft interior. The principal imaging system components are these: • A detector array and/or a scanning system, • Image acquisition hardware and software, • Image analysis and recognition computation, • A database of key threat images and spectra, • Display hardware, and • A network interface with other elements of the layered system.
From page 43...
... storage capability and significant computing power to provide the real-time detection capability of finding contraband hidden on individuals in a line of moving people. The recognition process must follow a strict hierarchy of algorithms with everincreasing thresholds in order to arrive at a positive indication with a high probability of recognition and low occurrence of false recognition.
From page 44...
... While this challenge is true for any security technology, imaging presents some unique problems, as the operator has direct, often visual, access to data about a passenger's body and clothing. This access raises both cultural issues of persons being under intimate observation and performance issues of interpretation of indications that may require subsequent physical access to the passenger's body.
From page 45...
... Unaided human search is possible, but it is not considered highly reliable compared with a computer-augmented search for well-defined threat targets. The human visual search process is time-intensive, as it is a self-terminating, exhaustive search, albeit guided by expectations and experience -- for example, knowing where to look first for potential targets.
From page 46...
... has developed a system for screening people that is based on active millimeter-wave technology. This method involves illuminating the subject with millimeter-wave radiation, but at a level low enough to prevent adverse health effects.
From page 47...
... . These portals allow security personnel to determine safely and efficiently if people -- whether visitors, employees, residents, guests, or passengers -- are transporting undesirable objects onto or off the premises.
From page 48...
... to penetrate dense materials, cause chemical damage to molecules, or knock particles out of atoms.10 Thus, it is non-ionizing radiation. The safety of millimeter-wavelength/terahertz energy has been established by a 2004 European Union study entitled THz-BRIDGE -- Tera-Hertz Radiation in Biological Research, Investigation on Diagnostics and Study of Potential Genotoxic Effects.11 Of note, this study has specific discussions on the little information that exists on corneal epithelial cells, which suggests that there are no adverse effects from exposure.
From page 49...
... . Agilent claims that the active millimeter-wave panel at less than 6 inches deep and under 30 pounds has demonstrated capabilities to locate concealed objects (explosive simulants,13 metals, and ceramics)
From page 50...
... This system was only recently announced, and as of this writing, limited information has been released by the company. Because this purely passive imaging technique relies solely on existing natural emissions from objects, it does not require human-made irradiation.
From page 51...
... SYSTEM CONCEPTS 51 Passive Millimeter-Wave Weapons-Detection System -- Brijot Brijot Imaging Systems, Inc.,17 in conjunction with Lockheed Martin, is developing an automated target-recognition-based concealed-weapons-detection system to detect and identify weapons underneath a person's clothing. It consists of a millimeterwave camera combined with a videocamera and special algorithm software.
From page 52...
... A technique to reliably identify the chemical structure of a suspect item remotely would improve baggage throughput by resolving alarms. Mass spectroscopy systems to detect explosives by means of vapor analysis are currently going through field trial investigations.


This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More information on Chapter Skim is available.