Method to Improve Location Accuracy of the GLD360

An algorithm change to the central processor of the network producing the GLD360 dataset is proposed to reduce the population of events with large (>5 km) location errors. In this study, we compare the data reprocessed using the proposed algorithm change to that from the realtime GLD360 dataset. The relative location accuracy using the National Lightning Detection Network as a reference is evaluated using data from July 20, 2013. With respect to the realtime dataset, the median location error of the reprocessed dataset decreased from 3.0 km to 1.7 km, and the 90 percentile decreased from 15 km to 6.5 km. The variation of the relative location error of the reprocessed dataset with local time is also investigated. The median location error is found to double near the local sunrise hours. This degradation in location accuracy is correlated with a drop in lightning event polarity estimation accuracy. Keywords—lightning location systems; VLF propagation; GLD360; performance improvements; location accuracy