On guard

A biosensor detection system that learns from its environment is being developed to provide UK soldiers with accurate data about a chemical or biological attack and limit false alarms.

The MoD has awarded engineering group Serco a £13m, two-year contract to supply nine Integrated Sensor Management Systems (ISMS). A standard ISMS system comes with 16 sensor interface units, each of which can be connected to eight detectors and can monitor an area of 5km2.

Serco’s system will work in tandem with newly developed biosensors to limit the number of false-positive warnings that can cause havoc on the battlefield, as was seen at the start of military operations in Iraq.

According to Serco project director Tony Rowe, the new system will plug a ‘capability gap’ in existing chemical, biological, radiological and nuclear (CBRN) detection systems. ‘Current CBRN networks are fairly crude communication- based systems that cannot process data,’ he said.

The system is designed to be ‘future-proof’ in that any new sensor technologies can be integrated into it with minor software updates.

A crucial element of the network is a new biosensor manufactured by Biral, which uses a combination of detection technologies to increase its accuracy.

Existing sensors in the UK characterise a particle by analysing its size and shape, while US sensors focus on its fluorescence. Fluorescence measurements are extremely good at distinguishing between biological and non-biological gases, but have problems with interferents, such as fuel oil from aircraft.

The Biral detector uses a patented laser-based system that combines the attributes of both sensor technologies, significantly enhancing its detection range and reliability, according to the firm.

Serco claimed that ISMS will eliminate the high number of false positives that plague existing inservice sensor systems. These can be set off by a variety of harmless substances, such as diesel exhaust or pollen. The new system’s software will manage a library of possible interferents that could give a false alarm. When the detectors pick up a possible hazard, the system analyses it against the stored data to determine whether it is a threat or not.

If a particle is detected for the first time and characterised as benign, it can then be added to the library and will be screened out if it appears again. By repeating this process, each sensor gradually adapts to its own environment, allowing the whole system to become more efficient.

Serco has developed a proofof- concept prototype for the system, and it is expected to be with the army by the end of next year.