Inspection of a Restricted Access Site Using UAV Perimeter Survey with the ARDUO Direction-Capable Gamma Spectrometer

Abstract

Under the comprehensive nuclear-test-ban treaty a State Party may request an on-site inspection to establish whether a nuclear explosion has taken place. The on-site inspection may include high- and low-resolution gamma spectroscopy surveys as well as environmental sampling and analysis. Aerial radiometric survey in particular has been demonstrated to provide efficient coverage of large areas. We have developed the Advanced Radiation Detector for Unmanned Aerial Vehicle (UAV) Operations (ARDUO) and are investigating its possible contribution to aerial radiometric survey in on-site inspection. This gamma spectrometer is direction-capable; it can point out the direction toward a source of radioactivity while in flight. We have collected data with the ARDUO flown over one and two point radiation sources in a grid survey covering 5,000 m $$^2$$ . With this data we demonstrate how directional techniques can be implemented in mobile aerial surveys to improve the spatial precision of the resulting radioactivity map. In particular, in an on-site inspection, an Inspected State Party may declare up to 50 km $$^2$$ of restricted-access sites, each of area up to 4 km $$^2$$ . We show how perimeter survey outside of a restricted-access site of area 920 m $$^2$$ with the direction-capable ARDUO permits a reconstruction of the distribution of radioactivity within the no-fly zone.