US Team's New Airborne Method Detects Radioactivity Within Seconds

US researchers have found a new method for faster and more accurate radioactive material detection from the air, according to the University of Michigan Engineering and Paul Scherrer Institute study. The system was described as capable of accurately locating a radioactive source within 6.6 feet (two meters) and measuring its activity within two percentage points of its true value.

Using a specialized physics-based math framework known as Bayesian inference, the study demonstrated the system could recognize both single and mixed radioactive sources during a six-second helicopter flyover equipped with airborne detectors. In the team's first field test in Switzerland, they placed known radiological sources on the ground, including mixed sources, and flew a military helicopter nearly 98.43 feet (30 meters) over it.

The aircraft, with a radiation detector in the cargo bay, detected the identity, activity, and location of the source using the Bayesian method, the study reported, despite a weak and heavily distorted signal during a single-pass flyover. Researchers noted the detections were achieved within seconds, unlike conventional techniques that take hours or days to evaluate radiological emergencies.

The lead author said the reduction in response time was made possible by recognizing the physics happening in the backdrop of events rather than enhancing computing power. The study reported that to locate the source below, the Bayesian framework constantly updates its statistical confidence by quickly comparing thousands of pre-existing spectral templates with blurred aerial data. The findings were published in the journal Nature Communications.