Snow (Standard, Compact, Mini and Micro)
The KU CReSIS UWB Snow Radar is a frequency-modulated, continuous-wave system that operates between 2–18 GHz (Figure 18). It is designed for centimeter-scale sounding of snow layering to depths up to ~100 m in the dry snow zone that constitutes the vast majority of West Antarctica. It is housed in a standard single-bay 19-in rack and includes four subsystems. The chirp generator produces fast (240 μs) 2–18 GHz linear frequency chirps with minimal phase distortion to permit low-sidelobe performance. The RF/microwave subsystem provides moderate transmit power(,1 W) high Tx/Rx isolation, receiver conditioning, and de-chirping by mixing with a transmit signal replica. The intermediate-frequency (IF) subsystem provides additional gain and near-range signal rejection by bandpass filtering the beat frequency signal to a user-selectable range appropriate to the AGL. Finally, the data acquisition subsystem digitizes the IF signal, performs hardware digital processing, stores data on solid-state hard drives, and provides real-time control and quick-look images of the recorded data. UWB Snow Radar typically operates at a 4-kHz pulse repetition frequency.