Vaisala's U.S. National Lightning Detection Network® (NLDN) is the most scientifically accurate and reliable lightning information system, monitoring total lightning activity across the continental United States, 24 hours a day, 365 days a year. It has been proven to deliver unrivalled performance with excellent location accuracy and detection efficiency, and is the only U.S. network capable of both detecting cloud and cloud-to-ground lightning while, at the same time, correctly differentiating between the two.