Abstract:
ABSTRACT
Luminosity variations of natural cloud-to-ground lightning flashes were studied by
analyzing a set of high speed video recordings. The frame rate and resolution of the
camera was 5000 fps at 512×512 pixel resolution. The frames were stored as black and
white sequence (SEQ) files which were converted to sequence of image files using the
software provided by the camera. Algorithms were developed to scan the image files
and extract maximum brightness of channels as well as maximum brightness at selected
locations along the channels. The variation of current along the channel was analyzed
by assuming that the brightness of the channel is directly proportional to the current that
flows through it. The study shows that there is a loss of current in lightning channels
when current flowing through the channel. The amount of current reduction increases
with the propagating distance. Preliminary estimates show that there is approximately
3% reduction in current when propagation from cloud-to-ground.
