Industry standards for the X-ray inspection of cargo

Innovative technology for the non-intrusive inspection of cargo and vehicles has rapidly emerged over the last decade to become a significant factor in port and border protection and homeland security. Several hundred high-energy mobile and fixed-site X-ray inspection stations are deployed throughout the world to examine passenger cars, trucks, trains, and shipping containers that transport goods bound for international destinations. Behind the scenes, cargo screening technology continues to be a story of innovation and change, driven by keen competition and a common mission to improve global security.

Evolution of systems

Early cargo screening systems were relatively slow and expensive to operate. They produced a limited resolution single-energy X-ray image, often using an isotope source such as Cobalt-60. The imaging software was rudimentary, and limited to simple controls such as pan and zoom, while computer processing speeds significantly limited inspection throughput. By contrast, most systems today are accelerator-based, which allows for higher energies, faster operation, and more precise controls. These systems incorporate software that takes advantage of improved computing platforms and features increasingly sophisticated analytics. Figure 1 illustrates how this power has paved the way for the use of dual-energy accelerator sources and advanced detectors to facilitate material discrimination, enabling inspectors to identify threat objects more quickly, based on their composition. For example, this truck cab is imaged by a manufacturer’s proprietary dual-energy system that classifies materials of interest by color and provides other advanced imaging features.

Likely progression

Future developments in cargo screening are likely to follow a common innovation trajectory that is fostered by market needs and new technology, while being strengthened by existing intellectual property and evolving industry standards. Figure 2 provides a simplified view of this model, where each color represents a distinct contribution to the innovation process The top section (see Figure 2 – in green) illustrates that innovation is often perceived as a circular path beginning with customer needs that are identified by a technology developer. The developer then creates application technology in the form of products to meet those needs. With numerous competitors in the market, suppliers are motivated to continually improve their products. However, a more nuanced understanding incorporates the role of component technologies (see Figure 2 – in red) and the core capabilities of the technology developer (see Figure 2 – in blue). Each of these constituents influence and are influenced by their respective technology and regulatory standards, which then ultimately impact the products available to the customer.

Component technologies and their standards are often driven by the needs of other markets and may only be tangentially connected with the market of interest. Consequently, developers often have minimal influence on these technology standards but will benefit by leveraging the investments already made by other organizations. ‘Components’ may be subassemblies (such as a computer graphics card) or entirely separate systems (such as a cloud computing service) that can be incor porated into a screening system to provide a complete customer solution. System providers benefit from these parallel technologies and component standards because they provide innovative insights and functional capabilities, such as interoperability, interchangeability, and known performance characteristics. In the case of cargo screening, there are many component technologies that are potential sources of future innovation. A few notable examples are described later in the article.

Because cargo screening is a youthful market with changing customer requirements and technology that is evolving to meet those requirements, existing industry standards are still in flux. This is beneficial for the cargo screening industry in that it provides ample room for innovation and development. As cargo screening technology continues to evolve and mature, the community will develop consensus in more areas and create additional standards. However, the standards process is slow and seldom speaks to the most current technology issues in an industry. For example, material discrimination is an important new feature offered by many cargo screening systems, yet there is little guidance from current industry standards to assess the performance of this technology.

 

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William Allan Reed PhD, commercial manager, Varian Medical Systems’ Security and Inspection Products Group, NV, US
Edition: Edition 56

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