Airborne Intensified CCD Observations of the 1998 Leonid Shower

Two coaxial microchannel plate intensified CCD systems (S-20 spectral response - sensitive from near IR to near UV but mainly concentrated in visual) were employed on the FISTA aircraft during the 1998 Leonid MAC campaign. During the 6 hours of observation on Nov. 17, 1998 a total of 230 meteors were observed in which 20 meteors were common to both systems. One system employed a 85 mm focal length lens with a field of view of 9.5 x 7.3 and a limiting sensitivity of +8.9 apparent stellar magnitude, while the second system employed a 50 mm focal length lens leading to a field of view of 16.3 x 12.0 and a limiting sensitivity of +8.3. Both systems had a constant elevation angle of about 75 degrees. The concept was to use coaxial systems in order to use correlation techniques to differentiate between true minor fluctuations in meteor light curves (indicative of in-flight fragmentation) and image intensifier noise. Results will be presented giving Leonid fluxes and light curve statistics as well as interpretation in terms of the probable physical structure of the meteoroids.