A Comparison of Processing Methods for the Oklahoma Lightning Mapping Array

Abstract

AbstractThe Oklahoma Lightning Mapping Array (OKLMA) has consisted of 17 Very High Frequency (VHF) sensors in two separate clusters separated by roughly 150 km since 2012. This large footprint of sensors is expected to benefit the spatial coverage, sensitivity and accuracy of the network (e.g., Chmielewski & Bruning, 2016, https://doi.org/10.1002/2016jd025159; Koshak et al., 2018, https://doi.org/10.1175/jtech-d-17-0041.1). The unique configuration of sensors facilitates the evaluation of treating the two clusters as a single, unified network. Network operators may wish to do this when processing networks in close proximity or for temporary network extensions during field projects. The 0000–0600 UTC period on 16 June 2019 included millions of VHF sources and thousands of flashes from isolated storms and a mesoscale convective system. The 0300–0700 UTC period on 12 June 2019 contained a single storm of interest proceeding scattered activity. The VHF solutions and their grouped flashes from the unified OKLMA network are compared to those generated from the combination of the two clusters each operating as separate, independent networks. The unified network processing not only required the substantially longer processing time, but also resulted in lower sensitivity and more noise, suggesting that the theoretical model of high accuracy and sensitivity with a large LMA footprint may not apply to this configuration. Additionally, relatively few (<10%) of the VHF sources observed by a single cluster of sensors matched a VHF source observed by the opposite cluster, suggesting that the sources mapped by each cluster of sensors were most often unique.