An Extreme-Low-Frequency Station for Global Lightning Monitoring

We propose a sparse ELF receiver network to continuously monitor the global distribution of intense lightning flashes, and hence, convective storms. Our goal is to provide more accurate location and better sensitivity than is now available. These improvements will be achieved by (1) correcting for variations in phase velocity of ELF sferics in the earth-ionosphere waveguide and (2) possibly using a multi-station, range-only location method. A compact, low-noise sensor and analysis system is proposed that provides continuous, near real-time storm locations. This system will contain event detection algorithms that replace the present method of detecting events by visual inspection or hardcopied data. These new detection algorithms are essential for an autonomous system. The effectiveness of the hardware design and improved flash detection and location algorithms will be evaluated in terms of two criteria: (1) minimum flash intensity required for detection and location (hence, minimum storm size) and (2) error in flash location. The evaluation will include the use and placement of a global network of stations. In addition to the primary application of monitoring storms, the new system has application to environmental monitoring and global warming.