The use of Global Positioning Satellites in the location of lightning storms as used by the Met Office´s arrival time difference Sferics detection system

The author describes how, since November 1987, the location of severe thunderstorms in the European area, bounded by 40 degrees Longitude (East and West) and 30 degrees to 70 degrees Latitude (North), have been reported by the UK Met Office using a system that uses the time of arrival of a received waveform generated by the returning stroke of lightning strikes. These receivers operate in the very low frequency (VLF) band centered between 8.1 and 11.7 kHz and are located in the UK and the Mediterranean. Due to VLF propagation, waveforms can be received from great distances so selected lightning atmospherics (Sferics) are detected and digitised waveforms are sent with the time of the first sample to the control station. Each receiver site (outstation) is unmanned, and stores all the data that it observes above a preset threshold, and is polled for data by the control station. A fundamental requirement of this system is accurate time and to this end, GPS is one of the external references that can be used to ensure that this is the case, and in the process helped in extending the useful range and precision of ATD Sferics detection system to that which is enjoyed today