Impulse response measurements on a 500-km meteor burst link

Using a wideband chirp sounder technique, the impulse response characterist ics of a 500-km meteor burst channel were investigated for the purpose of s tudying the fine structure of meteor trails giving rise to multipath propag ation, determining the channel delay spread statistics, and examining the c orrelation between multipath phenomena and meteor trail duration. To date, an analysis of these data has revealed that most of the time only a single dominant path exists between the transmitter and receiver. However, when mu ltipath conditions are encountered, many paths varying in both strength and duration may exist and can adversely affect communications. Fortunately, m ultipath conditions were observed in only about 30% of all echoes and, whil e seen in both short- and long-duration trails, were found to occur most fr equently during trails of longer temporal extent. In 90% of all measurement s considered, the rms delay spread was found to be less than 100 ns.