LINET-An international VLF/LF lightning detection network in Europe

Abstract

During the past years a lightning detection network (LINET) was developed at the University of Munich, which utilizes the low-frequency range (VLF/LF). It is steadily expanded and presently comprises about 90 sensors in 17 countries, covering an area from longitude 10° W-35° E to latitude 30° N-65° N. The network is serviced and continuously operated by nowcast GmbH, the official provider of lightning data for the German Weather Service, and offers real-time and historic data for many national and international scientific projects. LINET presents numerous options for users of lightning data, because it detects small signal amplitudes and, thus, is sensitive not only to weak cloud-to-ground strokes (CG) but also to cloud lightning (IC). The number of located IC discharges is large enough to attribute 'total-lightning'-quality to the network, otherwise accessible only by additional implementation of VHF technologies. Discrimination of CG from IC is achieved by means of a new 3D time-of-arrival (TOA) method, applicable within the sufficiently dense parts of the network. IC emission heights are extracted for each cloud event, which are thought to reflect the central region of the involved lightning channel. Position accuracy of strokes reaches an average value as small as ~150 m, provided that corrections for site-errors and propagation effects have been carried out. Important for many applications is the narrow distribution of errors around the mean, i.e. false locations ('outliers') rarely occur, enhancing the efficiency of cell-tracking and other nowcasting applications of lightning data. During international co-operations in scientific campaigns directed by DLR (Deutsches Zentrum für Luft-und Raumfahrt), a smaller version of LINET has been deployed and tested in four continents, Europe, South America, Australia, and Central Africa. In order to examine the achieved features in some detail lightning data have been compared between LINET and many national and global networks. © Springer Science+Business Media B.V. 2009.