Speaker
Description
The Meteosat Third Generation Lightning Imager (MTG-LI) has been operational since late 2024, providing continuous optical measurements optimised for lightning detection over Europe, Africa, and the Atlantic region. Beyond its nominal objective, MTG-LI has also demonstrated sensitivity to the optical flashes produced by fireballs.
ESA’s Planetary Defence Office (PDO), in collaboration with EUMETSAT, is adapting the MTG-LI lightning detection pipeline for the automated detection and characterisation of fireball signals. For this purpose, we are developing the LI Fireball Tracker (LIFT), a tool that systematically distinguishes fireball-induced flashes from lightning and extracts key fireball characteristics, including their brightness evolution and projected trajectories. These capabilities are being integrated into a data pipeline with the ultimate objective of delivering a comprehensive operational PDO fireball portal.
A key component of this effort is the recalibration of MTG-LI measurements from their nominal lightning-radiance framework to physically meaningful fireball energies. This will enable the conversion of observed optical signals into estimates of fireball luminosity and energy, providing a consistent basis for characterising fireball events and comparing observations across different events and instruments.
In ongoing collaboration with NASA, MTG-LI complements the fireball monitoring capabilities of the Geostationary Lightning Mapper (GLM) by extending coverage to the Eastern Hemisphere, enabling near-global geostationary observation of fireball activity. The fields of view of the two instruments also overlap, allowing for joint detection of the same events. This stereo viewing geometry facilitates the reconstruction of fireball trajectories in three dimensions (Silber et al., 2026), providing a pathway towards the determination of their pre-atmospheric orbital elements.
This emerging application of lightning imagers aboard weather satellites provides valuable new data for meteor science and planetary defence, while synergising with existing ground-based meteor networks to enhance event characterisation and observational coverage.