Interferometric Imagining of Lightning Initiation on LOFAR Data

Abstract:

We report progress in interferometric imaging of the initiation region of lightning via data collected by the Netherlands-based core of the Low Frequency Array of antennas (LOFAR). LOFAR achieves 1 nanosecond time resolution and meter-scale spatial resolution in lightning mapping from pulses observed in the 30-80MHz band via the 38 Dutch-based stations. Each station uses 6 dual-polarized antennas, each with sensitivity in the 10-90MHz range. This project will complement and enhance the previous work of the LOFAR lighting group of Groningen [Hare, BM, et al., Nature 568, 360363 (2019)] and [Scholten, O., et al., ESSOAr 10503153] in order to elucidate regions in which there are a high number of sources within a short duration of time. Furthermore, this analysis provides a more detailed image of the source rather than a singular data point. The overall aim of this project is to investigate techniques to improve upon the previously employed methods with the expectation of improving both spatial and time resolution of lightning sources. In doing so, we hope to uncover details about lightning initiation.