SEPARATION OF METEOR STREAMS FROM THE SPORADIC BACKGROUND

A cluster analysis procedure has been used to estimate the fraction of the sporadic interlopers (sporadis bias) identified as stream members among the observed meteor orbits. Using the artificial meteor orbits with the same distribution as the observed one, the sporadic bias is e stimated for the given threshold value of the orbital similarity D-c. It has been shown that in case of the radio meteor catalogues the D-c values given by the formula proposed in Southworth and Hawkins (1963)a nd in Lindblad (1971) correspond to the sporadic bias of 8-21%. For th e five radio meteor catalogues the values of D-c corresponding to the fixed bias equal to 19% and 15% are given.