"The Lightning Imaging Sensor is a small, highly sophisticated instrument that detects and locates lightning over the tropical region of the globe. Looking down from a vantage point aboard the Tropical Rainfall Measuring Mission (TRMM) observatory, 250 miles (402 kilometres) above the Earth, the sensor provides information that could lead to future advanced lightning sensors capable of significantly improving weather "nowcasting."
Using a vantage point in space, the Lightning Imaging Sensor promises to expand scientists' capabilities for surveying lightning and thunderstorm activity on a global scale. It will help pave the way for future geostationary lightning mappers. From their stationary position in orbit, these future lightning sensors would provide continuous coverage of the continental United States, nearby oceans and parts of Central America. Researchers hope that future sensors will deliver day and night lightning information to a forecaster's work-station within 30 seconds of occurrence — providing an invaluable tool for storm "nowcasting" as well as for issuing severe storm warnings.
The lightning detector is a compact combination of optical and electronic elements including a staring imager capable of locating and detecting lightning within individual storms. The imager's field of view allows the sensor to observe a point on the Earth or a cloud for 80 seconds, a sufficient time to estimate the flashing rate, which tells researchers whether a storm is growing or decaying." (NASA n.d.)