Lightning is the largest natural ignition source for wildland fire, and it is detected with its own sensor network. A ground-based network of radio receivers records the very low and low frequency electromagnetic pulse, the sferic, that each stroke radiates; comparing the arrival time of the same pulse at several stations locates the stroke by time-of-arrival multilateration, typically to within a few hundred metres, within seconds, and reports its polarity and peak current. Satellite-borne optical mappers, such as the Geostationary Lightning Mapper, complement this by imaging flashes continuously from orbit, seeing cloud flashes well but locating less precisely. For fire this is an ignition cue rather than a fire detection: a strike map plus a dry-lightning forecast tells detection resources where to look, and cloud-to-ground strokes carrying long continuing current are the ones most likely to ignite. The characteristic complication is the holdover, a strike that smoulders in duff for hours or days before emerging, so a strike location is a place to watch, not a fire to report. After this Concept you can use strike data to prioritise where a fire is likely to appear, and explain why the fire may not appear today.
Ground-based lightning detection locates strikes by capturing the broadband electromagnetic radio pulse ("sferics") radiated as current surges through the air during a strike, using a network of geog…