ROCKET-TRIGGERED LIGHTNING EVENT

Because thunder and lightning are unpredictable, the phenomena are best studied using triggered events. The technique involves launching a small rocket trailing a grounded copper wire into thunderclouds. The copper wire provides a conductive channel and creates a predictable path for lightning, allowing scientists to precisely focus their instruments and perform repeatable experiments close to the discharge channel. Using SwRI internal research funding, Dr. Maher Dayeh led a proof-of-concept experiment to image the acoustic signature of thunder. SwRI conducted experiments at the International Center for Lightning Research and Testing at the University of Florida, Gainesville, taking advantage of the state’s claim to the most lightning strikes per year in the U.S.

To map the acoustic signatures of thunder, Dr. Maher Dayeh and his team set up an array of of fifteen microphones, a meter apart, spiraling outwards from the site of the triggered lightning strikes. Using a few different processing techniques and a focus on higher sound frequencies, Dayeh eventually uncovered a distinct thunder signature.

SwRI reveals the first “images” of thunder:
http://www.swri.org/9what/releases/2015/thunder-image.htm#.VVFdS5PHjv1