Detection of the low frequency component in signals from the
Mediterranean Bolide on June 6, 2002-10-01
Ludwik Liszka, Swedish Institute of Space Physics
Douglas O. ReVelle, Los Alamos National Laboratory
A large bolide has been observed over the Mediterranean area on June 6, 2002.
Infrasonic signals in the range 0.5 - 4 Hz have been observed at Swedish infrasonic
station in Lycksele (64.6N, 18.7E). It has been found that signals contained a low
frequency component indicating a possible occurrence of gravity waves generated by the
impact of the bolide. The low frequency component has been enhanced in the data using
a wavelet-based filtering procedure generating a unit-variance frequency spectrum. The
procedure is enhancing weak signals if they are persistent in time within the analysing
window. The low frequency component was dominated by periods of 80 and 43 seconds.
Also 28 and 10 second periods were clearly visible.