Hyperbolic and interstellar meteors in the IAU MDC radar data

The radar meteor orbits of the most recent version of the IAU Meteor Data Center have been analysed and the hyperbolic orbits among them have been examined with the aim of to determining a real proportion of interstellar orbits in this database. It is shown from the tests that a large proportion of meteors with hyperbolic orbits is concentrated to the radiants of meteor showers and to the ecliptic plane. These belong to the orbits of typical interplanetary behaviour following annual and diurnal variation. In spite of this they highly increase a proportion of retrograde orbits. A vast majority of hyperbolic orbits, even for the highest measured velocities, may be considered as a consequence of measurement errors. We estimate that only a fraction of 10(-3) of the total numbers of 39 145 Harvard radar data in the MDC could be ascribed to real interstellar meteors. It means that from the number of 970 hyperbolic orbits in the Harvard radar catalogues only about 5% can be recognized as interstellar.