Two Methods for Correcting Range-Dependent Limitations of Lightning Mapping Arrays

Abstract

AbstractLightning Mapping Arrays (LMAs) detect very high frequency (VHF) radiation produced by lightning as it propagates; however, VHF source detection efficiency drops off rapidly with range from the centers of the arrays, which results in a maximum of source points over the center of the network for large datasets. Using data from nearly one billion detected sources of various powers, an approximation of VHF source detection efficiency (relative to the number of sources detected within 25 km of the center of the array) for the Oklahoma LMA is calculated for different ranges and source powers. The calculated source detection efficiencies are then used to normalize the VHF source data out to a range of 125 km, as a method for correcting the detection efficiency drop-off with range. The data are also sorted into flashes using a popular flash-sorting algorithm in order to compare how well flash sorting corrects for detection efficiency drop-off with range compared to the normalization method. Both methods produce similar patterns and maxima of the lightning location, but the differences between them are identified and highlighted. The use of a flash-sorting algorithm is recommended for future studies involving large sets of data.