Real-time and Post-processed Lightning Mapping by BOLT

BOLT (Broadband Observational network for Lightning and Thunderstorms) is an array of lightning sensors developed jointly by the University of Osaka and RAIRAN Pte. Ltd. in Japan.  BOLT consists of an array of about 14 low frequency (5-500 kHz) electric field change meters, sampled with GPS disciplined digitizers at 4 MHz. BOLT operates as a real-time lightning location system, and stores the raw data for further analysis at a later time if desired. While the real-time algorithm can only locate lightning in two spatial dimensions, using post-processing techniques allows detailed maps to be made of lightning flashes in full 3D. Starting in 2015, an effort was begun to improve the BOLT system along many fronts. The circuit for the sensing antenna was modified to allow for improved lightning mapping. The post-processing location algorithm was improved, so that BOLT now regularly locates over 1000 lightning sources per flash. Finally, the real-time display was completely overhauled, so that more information is displayed in a user-friendly format. Currently, we are working on improving the real-time location capabilities of the system. Presented is an overview of the current capabilities of the BOLT lightning mapping system.