Microwave backscatter coefficients of artificially grown first-year sea ice

The radar backscattering coefficient of simulated first year sea ice was measured at 5.2, 9.6, 13.6, and 16.6 GHz, using a dual-antenna FM-CW scatterometer. The measurements were corrected for antenna separation and beamwidth, to obtain true values of scattering coefficient. Above 15 deg, snow-covered and rough gray ice have similar angular responses, while the decrease in scattering coefficient with incidence angle is more rapid for smoother surfaces. True scattering coefficients and surface roughness data estimated with an antenna-beamwidth correction based on a physical-optics model give values close to those measured.