3-D Radiation Mapping in Real-Time with the Localization and Mapping Platform LAMP from Unmanned Aerial Systems and Man-Portable Configurations

Abstract: Real-time, meter-resolution gamma-ray mapping is relevant in the detection and mapping of radiological materials, and for applications ranging from nuclear decommissioning, waste management, and environmental remediation to homeland security, emergency response, and international safeguards. We present the Localization and Mapping Platform (LAMP) as a modular, contextual and radiation detector sensor suite, which performs gamma-ray mapping in three dimensions (3-D) and in real time, onboard an unmanned aerial vehicle (UAV) or in a man-portable configuration. The deployment of an unmanned aerial system (UAS) for gamma-ray mapping can be advantageous, as the UAS provides a means of measuring large areas efficiently and improving accessibility to some environments, such as multi-story structures. In addition, it is possible to increase measurement robustness through autonomous navigation, and to reduce radiation exposure to users as a result of the remote measurement. LAMP enables meter-resolution gamma-ray mapping through Scene Data Fusion (SDF) [1], a capability that fuses radiation and scene data via voxelized 3-D Maximum Likelihood Expectation Maximization (MLEM) to produce 3-D maps of radioactive source distributions in real-time. Results are computed onboard LAMP while it is flying on the UAV and streamed from the system to the user, who can view the 3-D map on a tablet in real-time. We present results that demonstrate the SDF concept, including a set of UAS flights where a 133Ba source is localized at a test site in Berkeley, CA and a handheld measurement in Fukushima Prefecture, Japan where the distribution of radiocesium(137,134Cs) released from the accident of the Fukushima Daiichi Nuclear Power Plant is mapped. The reconstruction parameters used for each measurement were identical, indicating that the same algorithm can be used for both point or distributed sources.