Man-portable radiation detector based on advanced source detection, identification, and localization algorithms

The search and identification of radioactive sources using man-portable radiation detectors is an essential part of the mission carried out by first responders, law enforcement and military personnel. Current approaches use ad-hoc techniques based on the experiences and training of individual users and suffer from low repeatability and long localization times. A systematic approach can significantly enhance the search capability by implementing the best search practices aided by processing algorithms embedded on ubiquitous mobile computing devices. In this paper we report on the performance results of the IDtector™ hand-held radiation detection system developed by Physical Sciences Inc. (PSI). The system combines real-time (1 Hz) threat detection and isotope identification with advanced search techniques for source localization in a compact and flexible package. The system is evaluated in the context of a wide-area search for a radioactive source. The use of PSI's Poisson Clutter Split (PCS) algorithm implemented on the system results in detection and simultaneous identification of a nominal 1 mCi source from 15 m stand-off range, while operating at a mission relevant false warning rate of 1 in 4 hrs. Source localization is facilitated by a Spin-to-Locate (STL) technique which uses shielding by the operator's body to modulate the radiation flux and estimate source azimuth. STL can be employed immediately following detection and results in < 15° RMS error of azimuth estimation.