Detection of fireballs in the Lightning Imager data

Abstract

ABSTRACT The Meteosat Third Generation - Imager 1 satellite, launched on 13 December 2022, features the first Lightning Imager instrument, a high-speed optical camera providing near real-time lightning detection over Europe and Africa. This study demonstrates that signatures of fireballs (i.e. bright meteors) can be detected in Lightning Imager data. We describe a method to analyse this data to determine the timing, light signal, and trajectory of fireballs, highlighting the instrument’s usefulness for bright meteor observation and proposing avenues for further research. By using known fireball locations and timings from external sources, the Lightning Imager data can be filtered to isolate ‘lightning events’ induced by the meteor. From this data set, the fireball light curve is computed by aggregating signal increases measured by instrument pixels. A trajectory is then deduced using a weighted average of pixel locations based on observed intensity. Three examples of fireballs detected by the Lightning Imager are presented, including a man-made meteor from space debris re-entry, with estimated timing, light curves, and trajectories.