Frequency domain interferometry (FDI) experiments were carried out on
two medium frequency spaced antenna radars located in New Zealand and
the Antarctic. These experiments were the first spaced antenna FDI exp
eriments on MF radar and allowed simultaneous measurements of wind, an
gular distribution, spatial interferometry, FDI range, and scattering
depth to be made. It was found that when correcting the FDI scattering
depths for the scale of the radar volumes, typically large on MF rada
rs, the adjustment should include a measure of the aspect sensitivity
of the scattering. FDI provides a means of clearly identifying thin la
yers, and the occurrence of such layers often appeared here to be rela
ted to fluctuations in the wind. A very interesting example was a thin
layer event that seemed to be closely related to a reversal of the wi
nd apparently caused by a change in phase of the semidiurnal tide; enh
anced turbulence following the event suggested breaking of the wave. M
ultiple frequency steps were used and, with analysis by frequency corr
elation functions, revealed the occasional presence of multiple scatte
ring features in the radar volume.