Jeppesen has added worldwide lightning data to its IR and visible satellite imagery maps. The World Wide Lightning Location Network, developed jointly at the University of Washington and University of Otago, allows for the detection of cloud-to-ground lightning using a network of 20 to 30 sensors around the globe. The sensors can detect lightning strikes up to 10,000 km away by measuring very low frequency radiation that emanates from the strikes. The lightning strike location accuracy is within several kilometers, and the detection efficiency detects a very high percentage of thunderstorms in real time. These additional data allow pilots to determine where convection and thunderstorms are located in worldwide areas, even where radar data are not normally available.