RADAR METEOR ATMOSPHERIC SPEEDS DETERMINED FROM ECHO PROFILE MEASUREMENTS

A backscatter radar echo from meteoric ionization is produced from the contributions from successive Fresnel zones as the meteor passes the specular condition. The time variation of the reflection coefficient g iven in terms of the Fresnel Function is related to the creation rate of zones and hence to meteoroid atmospheric speed. Such echo-profile s peeds have been measured using the AMOR facility (New Zealand) and com pared with meteoroid speeds simultaneously obtained using both spaced- station timing and whole-profile Fresnel oscillation patterns. The clo se agreement achieved confirms this simple technique-available to sing le station radar systems-as valuable in establishing meteoroid speeds. (C) 1997 Elsevier Science Ltd.