The Radar Beam
If the radar beam behaved in an ideal fashion many of the challenges associated with the interpretation of radar images would disappear, as would some of the "fun". Propagating a narrow electromagnetic beam through a thin fluid that has myriad density gradients using an antenna perched on a quasi-spherical Earth with a horizon distance measured in the 10's of kilometers ensures that the return signal will not be "ideal", and this is further exacerbated by orography, beam-filling issues, second trip echoes, anomalous propagation, and a host of other issues.
This module is intended to give the student an appreciation of some of the things that can alter the radar beam once it has left the antenna and moves through the atmosphere, returning eventually to the receiver, and to the images that the meteorologist must view. If the meteorologist is unable to separate what is relevant from what is an artifact produced by the beam's transmission and eventual return on the radar image in front of him (her), and do it rapidly, decision making may be impacted.