Amplitude-probability distribution of atmospheric radio noise

Atmospherics are assumed to be spike shaped with cxpon cnt ial upsurge and decay; their occurrence in time is Poisson-distributed . Thc distribution of thc pcak valuc is s how n to be lognormal. Under these conditions, thc amplitude distribution of atmospheri c noise is derived; it may be well approximated by the distribution of thc sum of a Raylcigh v('cto r and a vector with lognormally distributed amplitude. Thc rcsultin g di str ibution is un iqucly determin ed by threc physically m caningful paramctcrs and is in vcry good agrccmcnt witll meas ured di stribution s.