Radar observations of meteor trails, and their interpretation using Fresnel holography: a new tool in meteor science
[摘要] A Fresnel transform technique has been developed at Adelaide to analyseradar meteor echoes detected in the transverse mode. The genesis for thistechnique was the study of the structure of the scattering ionizationimmediately behind the head of the trail, in order to deduce the degree offragmentation of the ablating meteoroid. The technique has been remarkablysuccessful in not only giving insight into the fragmentation of meteoroids,but also revealing other significant features of the trails includingdiffusion, lateral motion of the trail during formation due to wind drift,and phase of the scattered signal in the vicinity of the head of the trail.
A serendipitous outcome of the analysis is the measurement of the speed anddeceleration of the meteoroid producing the trail to a precision farexceeding that available from any other method applied to transverse scatterdata.Examples of the outcomes of the technique applied to meteor echoes obtainedwith a 54MHz narrow beam radar are presented.
