Direction Finder (DF) 1 : An electronic field sensor which determines the strength, polarity, time, and relative bearing of a cloud-to-ground lightning flash and transmits this data to a position analyzer
The Canadian Interagency Forest Fire Centre (CIFFC), Glossary of Forest Fire Management Terms, Manitoba, Canada 2003. http://bcwildfire.ca/mediaroom/Backgrounders/2003_ Fire_Glossary.pdf, (For Fr - Canad) {474}