THE INTERFERENCE ENVIRONMENT OF RADIO NOISE FROM LIGHTNING

Abstract

The  paper furnishes  a  review  and  an  overview of  radio  noise  from  lightning  as  a  source of interference  to  analogue and  digital  Communication.  The  parameters  of  the  different  forms of  noise  necessary  for  assessing the  interfering  effect  of  the  noise  are described. Available information on thunderstorms,  thunder-clouds,  convection  cells  and  lightning  are  reviewed and  their  limitations pointed  out.  There follows a  description of  how  the  source,  propagation  and  receiver  characteristics  determine  the  structure  of  atmospheric  noise  as  received  at  a  point  of  observation.  The  natural unit  for  this noise  is  the noise  burst  rising from  one  complete  lightning flash.  The  parameters of  the  noise  burst  as a  whole  and  its  structure  determine the interference environment. A  historic review of atmospheric literature studies  show that  it  is currently of  importance  only  in  the  tropical  regions  of  the world for which the available data  are  very defective.  New  data are  furnished.  The  contribution  of  atmospheric  noise  for  background  interference even  in  remote  places  for  radical  astronomy  at  VHF  is  furnished.  The  importance  of  atmospheric noise occurring sporadically in high  values  for short intervals at  VHF  and  higher frequencies  in  the  tropics  is  brought out.