Design and Implementation of GLM Gridded Imagery for Operations and Research

The Geostationary Lightning Mapper (GLM) on the GOES-R series of spacecraft has a 500 frame per second CCD detector array that observes pulses of light produced by lightning. However, the data are disseminated as hierarchically clustered point data, so reconstruction of the spatial footprint of the detections is necessary before the GLM data can be displayed as imagery - as is natural for overlay on other satellite imagery.

This study illustrates the steps taken to create such imagery. They are: renavigation to fixed grid coordinates; accumulation of flash, group and event properties at discretized event locations; the restoration of the event corners, and regridding of the individual event footprints onto the GOES-R Advanced Baseline Imager fixed grid at 2 km over a 1 minute window. The approach augments the information available in the L2 point data product, and results in seven gridded products: flash and group extent density, flash and group centroid density, average flash and group area, and total optical energy. These products cover the most basic accumulations of the properties in the L2 data without application of additional algorithms. A version of this processing has been implemented in a pre-operational trial at the US National Weather Service using the same core as an open-source package available for community use.