Characteristics of Radio Echoes from Meteor Trails IV: Polarization Effects

Observations have been made of radio echoes from meteor trails at 55 Mc/s in order to test the theoretical estimates by Kaiser and Closs of plasma resonance effects. The aerial array consisted of two Yagis mounted with mutually perpendicular planes of polarization on a common axis. The polarization effects observed are in good agreement with prediction for both short and long duration echoes, but some unexpected results were obtained for meteor trails with line densities in the transition region of 10 12 electrons cm -1 . Some calculations have been made of the effect of the finite meteor velocity upon observed polarization effects, and are in good agreement with observation. In addition to the polarization measurements, the relationship between the amplitude A and duration T of long duration echoes was investigated. An empirical relation of the form A is proportional to T 0.3 was found, in contrast to the predicted law A is proportional to T 3/16 . It is suggested that the discrepency is a result of diffusion by turbulence in the atmosphere.