An Operational System for the Remote Location of Lightning Flashes Using a VLF Arrival Time Difference Technique

An operational system for the remote location of lightning flashes at ranges of thousands of kilometers is presented. The vertical electric fields of VLF radio atmospherics (sferics), together with time data, are observed at a network of just seven outstations dispersed over the United Kingdom and the Mediterranean. These data are forwarded to a control station, which locates individual flashes in real time using arrival time difference (ATD) techniques, analogous to Loran-C, and generates regular reports for automatic distribution. The service area covered exceeds 30 degrees to 70 degrees N, 40 degrees W to 40 degrees E; flash location accuracy is 2-20 km; and approximately 400 flashes per hour can be located.