Airborne pulse-limited radar altimeter return waveform characteristics over ice in the Beaufort Sea

Pulse-limited radar data taken March 1978 with the 13.9 GHz AAFE (Advanced Applications Flight Experiment) altimeter from 1500-m altitude over ice in the Beaufort Sea are registered to high-quality photography. The variations of the radar return waveform shape and signal level are correlated with the variation of the ice type determined from photography. The AAFE altimeter has demonstrated that the return waveform shape and signal level of an airborne pulse-limited altimeter at 13.9 GHz respond to sea ice type. The signal level responded dramatically to even a very small fracture in the ice as long as it occurred directly at the altimeter nadir point. Shear zones and regions of significant compression ridging consistently produced low signal levels. The return waveforms frequently evidenced the characteristics of both specular and diffuse scattering