Radar Observations of Meteors

Abstract

A meteoroid entering the atmosphere produces a transient plasma that due to ambipolar diffusion expands to a trail and drifts with the local wind. Radar detection of meteor plasma with different kinds of radar systems have enabled studies of meteor astronomy and meteoroid atmosphere interaction processes, such as meteoroid ablation and fragmentation. Specular meteor radars detect meteor trails aligned perpendicular to the radar line-of-sight and have been used to estimate mesospheric wind fields and temperatures, as well as meteoroid populations, including previously unidentified meteor showers. High-power large-aperture radars have been used to study meteor head echoes and non-specular trail echoes. The latter are caused by a combination of magnetic field and dusty plasma effects, and have been used to get precise horizontal wind profiles in the mesosphere and lower thermosphere. Meteor head echo observations have enabled the low-mass component of meteor showers and the sporadic complex to be studied, in addition to the small-scale details of meteoroid-atmosphere interaction processes.