[Meteor-Scatter] VHF Radar question

[Fabry Adrian]

Hi all,

I use to monitor VHF Radar of Oswin,
http://www.iap-kborn.de/radar/Radars/OSWIN/meteor_aoa01.htm
My question is how is the radar able to distinguish betwen meteor trail
reflection and ES or other
kind of reflection ? Is that number of events realy meteors ? 
Also I'm confused about the meaning of Zonal zenith angle and Meridional
zenith angle.

Any info will be appreciated.
TNX & 73 de Ady / YO2NAA