AS&E Technology - is it worth it?

Implications: AS&E has heavily and successfully marketed its backscatter X-ray technology for several applications.  Backscatter X-ray has its strengths but also weaknesses - especially for large dense cargo containers. When properly applied, it can reveal certain concealed items, but are these limitations worth the cost.

Analysis: Backscatter X-ray is a technique that can complement transmission X-ray.  While both use X-ray sources, transmission X-ray looks at the intensity of X-rays that pass through an object, making it useful for high contrast objects (e.g. metallic objects such as guns and knives).  Backscatter looks at X-rays that are reflected back off an object, which makes it more useful for low density objects such as plastics. However, backscatter X-ray has one critical liability: it only penetrates a few centimeters into one side of the container being scanned.  This means that typically only a portion of each container is subjected to the backscatter X-ray inspection,  Scanning all surfaces of, say, a suitcase, would require running the bag several times in different orientations (impractical in many security applications) and even then it would only "see" what's close to - or inside - the container walls.

Any attempts to position backscatter X-ray for Cargo screening as a complete solution would be disingenuous.  As a supplement to transmission X-ray (which is typically how it's configured), it has some merit for certain types of containers and contraband configurations.  Backscatter X-ray components are slightly more expensive than conventional transmission X-ray.

For baggage, AS&E only recently brought its transmission X-ray system up to the levels of others in the industry - its Gemini cabin bag X-ray is the first AS&E unit to use dual energy X-ray transmission (along with its backscatter X-ray) to better discriminate organic from inorganic materials even though companies like Rapiscan, L3 and Smiths have used dual energy X-ray for many years.

Scanning passengers using a microdose Backscatter X-ray has the potential for revealing both high and low contrast objects hidden underneath clothing at passenger checkpoints. Privacy is an issue and many experts believe that so called modesty algorithms being considered (by AS&E and others) have the potential for "throwing the baby out with the bathwater" - i.e. covering up real threats in those locations.

A careful analysis and understanding of the end user application, types of containers/ passengers and threats likely to be revealed by backscatter X-ray would be needed to assess if it's worth the additional cost.