Relationship between Horizontal Wind Velocity and Normalized Surface Cross Section Using Data from the HIWRAP Dual-Frequency Airborne Radar

Abstract The High-Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP) dual-frequency conically scanning airborne radar provides estimates of the range-profiled mean Doppler backscattered power from precipitation surface. A velocity–azimuth display analysis yields near-surface horizontal wind vector υ h in cases which is present throughout scan. From surface return, normalized cross section (NRCS) obtained, which, by a method previously described, can be corrected for path attenuation. Comparisons between attenuation-corrected NRCS are used to derive transfer functions that provide data under both rain rain-free conditions. reasonably robust function found using (⟨NRCS⟩) over scan along with filtering based on Fourier series NRCS. approach gives good correlation coefficients ⟨NRCS⟩ at Ku band incidence angles 30° 40°. degrades if Ka-band rather than band.