Spatial Correlations: examining the relative agreement between temporally correlated flashes from three different lightning detection systems

The occurrence of cloud to ground lightning within 5 nautical miles effectively stops all outdoor activities on an Air Force installation. Absent visual observations, these warnings are often triggered by occurrence inferred by ground based lightning detection networks. Accurate geolocation of these detected events is crucial to maximizing safety while minimizing operational downtimes. Thirty days of lightning data collected from an array of nine Low Frequency/Very Low Frequency (LF/VLF) Time-of-Arrival (TOA) lightning sensors installed in the vicinity of the US Air Force Academy (courtesy of TOA Systems Inc.) are analyzed in an effort to ascertain network performance relative to Vaisala's National Lightning Detection Network® (NLDN) and the Earth Networks Total Lightning NetworkTM (ENTLN). Here, the spatial locations of temporally correlated flashes detected by all three networks (coined “temporal triplets”) are compared against one another to characterize the relative spatial agreement (or disagreement) between networks. Using latitude/longitude pairs from each of the triplets, triangular areas are used as a comparative metric to quantify geolocation differences, with smaller areas indicating greater relative agreement. An analysis of the spatial distribution of this metric will be conducted to determine if configuration biases exist due to the complex topography of the area.