Meteor Echoes Research Articles

LVII. The diffraction of radio waves from meteor trails and the measurement of meteor velocities

Abstract The necessity for studying the reflected amplitude of radio waves from meteor trails in time intervals of the order of milliseconds is discussed, and automatic equipment is described, using pulse technique, which records this information photographically. Theoretical considerations indicate that fluctuations in reflected amplitude should occur as the meteor crosses the region of the perpendicular from the observing station, the problem being analytically identical to the diffraction of light at a straight edge. It is shown experimentally that initial amplitude fluctuations are associated with many meteor echoes and possess the correct ratios of zone durations predicted by the diffraction theory. Since the times to traverse specified zones are measured, the experiment leads directly to a measure of the velocity of individual meteors. The technique has been applied to the velocity measurement of the meteors from known showers and the results are shown to agree with earlier photographic and visual m...