부산대학교 도서관

We developed a high-sensitivity airborne multichannel ultrawideband (UWB) frequency-modulated continuous-wave (FMCW) radar for snow depth measurements. This low-transmit power eight-channel radar has a near-ideal point target response and provides a multilook ability. We developed a T-shape Mills-Cross antenna array to obtain a small, overlapped footprint. We integrated it with a 2 degrees of freedom (DOF) gimbal mechanism to correct pointing errors in the roll and pitch movements of the aircraft. We performed airborne UWB radar measurements in conjunction with in situ characterization and dielectric measurements with a monopole dielectric probe over snow in Grand Mesa, CO, USA, from 24th January to 14th February 2023. The radar mapped top and bottom snow interfaces and internal density changes of 1.2–2.6 m of snow with high signal-to-noise of about ~45 dB with only 10 mW transmit power. The multichannel system with gimbaled antenna mount allowed us to capture quasi-specular returns even with aircraft roll deviations as large as 15°. The comparison between radar data and in situ measurements shows excellent agreement between the two in terms of snow depth and internal snow layers.