Some properties of oblique radio reflections from meteor ionization trails

Certain characteristics of radio signals, propagated by reflection from meteor ionization trails from a low-power continuous-wave transmitter 960 km distant, were studied at radio frequencies of 23.2, 46.4, and 92.8 Mc. In particular, the percent of the total time that meteor reflections were detectable at each frequency is presented, and shown to be in qualitative agreement with theoretical expectations. Simultaneous recordings were also made of signals from a second remote transmitter operated at 23.1, 46.2, and 92.4 Mc, and located at various distances along, and at right-angles to, the propagation path. From the percent time that signals received from the second transmitter were coincident with those from the first, it is concluded that reradiation from the numerous, low-density trails is highly directional, and that the fading, long-enduring echoes from the relatively-infrequent, high-density trails are considerably less directional. When the transmitters were spaced in a direction perpendicular to the propagation path, the signal coincidence decreased much more rapidly with transmitter spacing than when the transmitters were spaced along the propagation path.