Lightning Imager A Spot

Lightning Imager

Real time lightning location and detection

Lightning Imager A Spot
Lightning Imager A Spot

The Lightning Imager (LI) provides a real time lightning location and detection (cloud-to-cloud and cloud-to-ground lightning, with no discrimination between the two types).

Last Updated

05 March 2021

Published on

21 May 2020

The imager is a new instrument, not based on any previous heritage from the Meteosat Second Generation series.

The LI uses detector elements arranged in a detector array covering the whole Earth (no scanning mechanism).

The total energy received from the photons are sensed by each detector element and integrated during the integration period. These are then compared with the LI Trigger Threshold and if the energy exceeds this threshold, it is identified as an LI triggered Event (Figure 1).

The Lightning Imager (LI), on board the MTG-I satellites, will continuously measure at a wave-length of 777.4 nm with a very narrow bandwidth, with a spatial resolution 4.5 km at sub-satellite point, triggered by a variable threshold — optical pulses initiated by lightning emitting energy of larger than between 4 and 7 µJm-2sr-1.

MTG LI Pixel Events
Figure 1: LI triggered event

The field of view (FOV) (Figure 2) of the LI instrument is covered by four identical cameras on the instrument, each covering one out of four domains on the observable Earth disc.

MTG Lighning Imager Field of View
Figure 2: Field of view of the Lightning Imager instrument

Products derived from the instrument data will be arranged around following three categories:

  1. Events — what the instrument measures, a triggered pixel in the detector grid.
  2. Groups — neighbouring events in the same integration period (1 ms), representing a lightning stroke.
  3. Flashes — collection of groups in temporal and spatial vicinity (XX km, YY milliseconds), representing a lightning flash.

The MTG-I LI instrument will complement the NOAA Geostationary Lightning Mapper (GLM) on the GOES-R and the GOES-S satellites and CMA Lightning Mapper onboard the FY-4 satellite series.

MTG Lighning Imager Categories
Figure 3: LI product categorisation