METEOR OBSERVATIONS BY THE ARECIBO 430-MHZ INCOHERENT-SCATTER RADAR .1. RESULTS FROM TIME-INTEGRATED OBSERVATIONS

The paper discusses an incoherent scatter radar (ISR) power profile in terference detection and meteor filtering technique and presents the m eteor interference statistics derived from the Arecibo 430 MHz ISR. Th e statistics obtained from the Arecibo ISR are comparable with the met eor statistics obtained by other radar and optical techniques. Using t he hourly rate of meteor flux, the average visual magnitude of the met eors is estimated to be as faint as +14, probably, the faintest ever r eported. For low echo meteors, the mean ablation height exhibits a log arithmic relationship with the returned power below 105 km. However, o nce the echo power exceeds a certain threshold, the mean height remain s constant at 107 km for all meteors irrespective of their returned po wer. The unique aspect of the meteor trails reported here is that they are observed in the radial direction of the radar beam. The lack of a spect sensitivity and the high meteor rate detected by the Arecibo 430 MHz system seem to suggest that the scattering mechanism in the UHF r ange of frequencies may be different from the mechanism operating at V HF. Some future prospects of exploiting meteor trails to study the neu tral wind and other aspects of the meteor region are also proposed.