Meteor Observations with an MF Radar 1

We conducted meteor echo observations using the Buckland Park MF radar (35 S, 138 E) at 00:40{05:45LT on October 22, 1997. In addition to the usual full correlation analysis (FCA) technique to measure horizontal wind velocities from 60 to 100 km MF radars have a potential to detect meteor echoes and infer winds through their Doppler frequency shifts. Because of the relatively low radio frequency employed MF radars have a great advantage of providing wind information well above 100 km altitude, where very few techniques can measure wind velocities. There is a limitation which should be noted as well. The observations are possible only during night time when the electron density of E-region is low enough for the radio wave to penetrate into the upper region. We detected 233 underdense meteor echoes from 80 km to 120 km with a mean height of 104.4 km. Although the transmitting antenna beams were steered toward o -zenith angles of 25 , almost all the echoes were received outside of the main lobe, indicating that conventional MF radar systems with a broad transmitting beam can work well for meteor observations. Bi-hourly wind pro les were obtained from 94 to 114 km altitudes. The pro les revealed a clear wave structure with a downward phase progression with time. FCA winds from 80 to 100 km were also estimated, and a continuous wind structure was obtained from FCA to meteor heights. Note that the present observations happened to be conducted during a major meteor shower activity. However, a majority of the underdense echoes were from non-shower meteors, and observations during non-shower periods will also yield enough information.