A 2D full-wave simulation of ordinary mode propagation has been develo
ped in an effort to model effects seen in reflectometry experiments bu
t not properly explained by 1D analysis. The geometric fall-off of the
fields, together with the effects of both refraction and diffraction,
considerably modify the results obtained. The now commonly seen exper
imental observations of large amplitude and phase variations of the ec
ho signal and occasional ramping of the phase can be explained by thes
e 2D effects in the presence of fluctuations.