Compact Airborne C-Band Radar Sounder

We describe a lightweight wideband C-band radar sounder, which is designed for use in a small unmanned aerial vehicle, primarily for measuring snow and ice. The waveform used is a gated frequency modulated continuous wave, which enables transmission at low power with relatively high energy in the compressed pulse. Gating allows use of a single antenna, reducing the influence of the direct wave on the systems´ dynamic range. The radar operates at 5.3-GHz center frequency and has a bandwidth of 1 GHz, for a nominal range resolution of 15 cm in air or 12 cm in snow. Laboratory testing and airborne acquisition of data over the glacier Hardangerjøkulen show that the radar appears to work well for the intended purpose of measuring snow layer thickness.