  The initial results of a two year simultaneous optical-radar meteor campaign
are described. Analysis of 105 double-station optical meteors having plane of
sky intersection angles greater than 5 degrees and trail lengths in excess of 2
km also detected by the Middle Atmosphere Alomar Radar System (MAARSY) as head
echoes was performed. These events show a median deviation in radiants between
radar and optical determinations of 1.5 degrees, with 1/3 of events having
radiant agreement to less than one degree. MAARSY tends to record average
speeds roughly 0.5 km/s and 1.3 km higher than optical records, in part due to
the higher sensitivity of MAARSY as compared to the optical instruments. More
than 98% of all head echoes are not detected with the optical system. Using
this non-detection ratio and the known limiting sensitivity of the cameras, we
estimate that the limiting meteoroid detection mass of MAARSY is in the 10-9 kg
to 10-10 kg (astronomical limiting meteor magnitudes of +11 to +12) appropriate
to speeds from 30-60 km/s. There is a clear trend of higher peak RCS for
brighter meteors between 35 and -30 dBsm. For meteors with similar magnitudes,
the MAARSY head echo radar cross-section is larger at higher speeds. Brighter
meteors at fixed heights and similar speeds have consistently, on average,
larger RCS values, in accordance with established scattering theory. However,
our data show RCS ~ v/2, much weaker than the normally assumed RCS ~ v^3, a
consequence of our requiring head echoes to also be detectable optically. Most
events show a smooth variation of RCS with height broadly following the light
production behavior. A significant minority of meteors show large variations in
RCS relative to the optical light curve over common height intervals,
reflecting fragmentation or possibly differential ablation.
