Stand off detection of CBR agents has been a long held desire of CBRN responders in the military and civilian realm for decades. Each of the three types of agent, chemical, biological and radiological, pose their own challenges to the scientists and industrialists tasked with ways of detecting agents early and safely.
There are some problems that are common to all of them. The first is cost, weight and power. It is not just the cost of the individual sensor that needs to be factored in, but also the team that needs to go out into the release, take samples and return them to a lab that has to verify them within a useful timeframe. The majority of systems have a clear relationship with distance and power. If you want to have something that can detect to single digit meters, then it can be handheld or in a backpack (Pendar’s X10 or Alakai’s Pried), once you start getting out to tens, hundreds or thousands of meters then it needs a significant amount of power and needs to be vehicle mounted (Bruker’s Sigis2 or Chemring’s I-SCAD) or mounted on a building (Lockheed Martin’s Windtracer)
Another is the need to make the device safe for users and individuals that might be in the area. This is not in case the device falls on them, even though in some cases this would be a hazard, but eye safe. Many chemical and biological stand off systems use active lasers or optics, that need to be within the eye safe range. Once you start ramping up the power to allow it to reach out to a chemical tanker, for example, several kilometres away the intensity of the beam can be enough in some older systems to cause eye damage. Now sensible people might say that if you are close to a significant biological or chemical release that eye damage is the least of your problems… but it is not just CBRN forces that use lasers. The proliferation of lasers on the battlefield, from signifying targets to laser dazzlers forcing drivers to stop, has caused a number of injuries and as such there is an effort to ensure that permanent eye damage is not done. It is not just the range that is a driver for powerful lasers, but also the type of agent. Passive systems, such as Bertin’s Second Sight, require a vapour cloud, that can be distinguished from the background, but not all chemical warfare agents are volatile, the Novichok, V and H agents are thick, and unlikely to give off enough to provide a cloud. If you want to detect these you need to be able to have an active laser that can properly interrogate the puddles or deposition. Improvements are being made, but active stand off is often the culprit for eye safe transgression.
Chemical
Chemical stand off is the most likely of all stand off detectors to be found in the experts’ toolkit. Admittedly it is more common in the military than civilian fields, but work done by Federal research organisations like IARPA means that it is also increasingly likely to be seen in clandestine lab busts. Improvements in technology and libraries mean that it is not just chemical warfare agents that are being detected but also narcotics and explosives. This capability is changing the way that organisations think about stand-off.
Previously the military wanted to know that significant amount of hazardous substances were coming their way, so they could gain vital seconds to don personal protective equipment. Even within the military sphere this shifted into small team concepts, such as wanting to know whether chemical breakdown products could be detected around air conditioning/filter outlets, gaining vital intelligence on whether that building houses a clandestine lab. Now we are in the situation where law enforcement can use stand off to do quick categorisation of a crime scene: to know that ‘this’ is baby powder while ‘that’ is fentanyl. These missions sets are seeing new technology join infrared spectrometers, like hyperspectral and quantum cascade lasers.
The traditional mission of sensing at extended distances has shifted from a fixed sensor to a mobile one. Minerva in the UK or Deep Purple/Integrated Early Warning (CBRNe World 2016-5 & 2019-3) in the US, shows that the trend is now towards putting tried and tested detectors on robotic platforms and handing the data back to the network, rather than experimental systems reaching out thousands of meters.
Anyone that is interested in learning more about stand off chemical detection can have a gander at what NIST thinks.
Radiological
This is one of the few areas in the history of the magazine (15 years and counting) where we have seen genuine improvements. In Winter 2006 we published an article by Tom Cousins from DRDC on something called a Simultaneous Multispectral Imager (SMSI), which employed a telescope to collect light which it then split so it could image a scene in six different wavelength bands. Now gamma cameras, while not ubiquitous are at least familiar to people. These are different to the ones used in public health, however, and are instead used to quickly locate areas of high radioactivity. While they were a thing of science fiction now you can use one from H3D, Mirion or a number of other companies.
It is not just gamma radiation that can now be detected at a stand off range. As part of the European Funded GIFT project we were able to see first hand the work that Johan Sand and first STUK and now the Tampere University of Technology (TUT) have done on an alpha camera. Detecting alpha radiation, as shown in the Litvinenko murder is a nightmare for responders, involving the detector being held millimetres above the potential contamination. While previous Alpha cameras in the past required the area to have all light sources removed, so the minute amount of radioluminescence could be detected, Johan managed to get similar results in normal daylight, and hopefully once demand increases a commercial product can be launched.
Biological
Biological stand-off has been worked over at least as long as chemical, but the maturity is a long way behind. Fundamentally the reason for this is the sheer amount of ‘noise’ out there. A lot of chemical stand off detectors work by knowing what the background is, and then analysing areas that suddenly change. It is rare that this background will change significantly without something going wrong – which is why many stand off chemical detectors are used at petrochemical plants. With biological stand-off, we frequently have enormous natural changes, one of them is called ‘Spring’ and another is called ‘Summer.’ Pollen poses a massive challenge to some biological stand off detectors if it luminesces in the same range that the sensors are looking for.
The US National Academy found huge problems with the whole biological stand-off infrastructure, including a shortage of staff, standards and test facilities. This is largely down to a shortage of customers. Radiation and chemical stand off have non-government customers (nuclear power plants and chemical facilities), but there isn’t a comparable profitable base for biological stand-off. If it isn’t for a government customer it is not going to happen. If the government is unsure about the threat then it is going to be unsure about the return on investment, and this is not a system that can be re-purposed for naturally occurring pathogens.
There are some products out there, like Lockheed Martin’s Prowlr and SESI’s JBSDS, but these have had limited application. Even point biological detection is difficult, as evidenced by the Biowatch programme, and there has not been a queue of customers hoping to solve this even harder problem. Bio stand-off tend to be Lidar, and even though government research projects keep having a go at it there hasn’t been a breakthrough. Block with their quantum cascade lasers are hoping that they have it, but in the past there has been a huge difference between lab and field capability.
Conclusion
Well-funded research projects in the chemical space, and the need to deal safely with nuclear power plants will drive innovation in these sectors and responders, both military and first responder, will benefit. Handheld devices in both these sectors exist, and doctrine is being developed for them. Biological stand-off lags a long way behind due to the challenges of the environment and a lack of investment in the sector. It’s unlikely that any technology will be mature enough in the next five years to see one placed in any CBRN responders hands.