WWLL global lightning detection system: Regional validation study in Brazil

An experimental lightning detection network, the World Wide Lightning Location network (WWLL), is being developed to provide real time global coverage with 10 km location accuracy and at least 50% detection efficiency. This paper provides a worst case'' analysis of WWLL location accuracy in Brazil where the VLF lightning receivers that make up the network are very distant (> 7000 km). Through comparison to a local lightning detection network, we analyze the detection accuracy in Brazil with respect to time, location, and peak current of lightning strokes. In this study, we find that WWLL detection is highly dependent upon the peak return stroke current, resulting in detection of about 0.3% of the total lightning strokes. However, the detected strokes have a location accuracy of 20.25 +/- 13.5 km and a temporal accuracy of 0.06 +/- 0.2 ms, providing a good overview of regions of overall global lightning activity in real time.