First Observations of G‐Band Radar Doppler Spectra

Abstract

In the last three decades mm wavelength radars within the Ka-bands and W-bands have proved to be paramount tools for cloud and precipitation process studies (Kneifel & Moisseev, 2020;Ori et al., 2020) and long-term cloud monitoring (Kollias et al., 2020;Stein et al., 2015;Tridon, Battaglia & Watters, 2017). This success has been driven by their larger sensitivity to small droplets and ice crystals (Lhermitte, 1990), their superior spatial resolution, and their reduced susceptibility to Bragg scattering compared with centimeter-wavelength radars in the S, C, and X bands (Kollias et al., 2007), whereas their portability and compactness have made them suitable instruments to be deployed on ships (e.g., Protat et al., 2016), aircraft (e.g., Walker McLinden et al., 2021, and spacecraft. The latter application is demonstrated by the W-band CloudSat and the Ka-band GPM radars (Battaglia et al., 2020, and references therein). Synergistic measurements which combine multifrequency centimeter and millimeter wavelength radars (e.g.,

G-Band FMCW Doppler Radar for Close-Range Environmental Sensing

“…Further recent systems include: ViSAR, a high power pulsed travelling wave tube SAR system at 235 GHz which uses the shorter required aperture lengths at G-band to produce videorate SAR imagery [33], [34]; a solid-state pulsed Doppler cloud-profiling radar at 199.5 GHz named GRaCE, where Gband provides better cloud penetration than lidar and greater sensitivity to particle size distribution than W-band and below [35] as well as a pulsed radar cloud-profiling satellite payload technology demonstrator at 238 GHz [36]; a differential absorption radar named VIPR operating around 170 GHz used for cloud humidity profiling from the ground and air, utilizing the presence of the 183 GHz water vapor absorption line for the sensing technique [37]- [40]; and a mechanically scanned FMCW imaging radar at 223 GHz to research alternatives to lidar automotive sensing [41].…”

G-band FMCW Doppler radar for sea clutter and target characterization

“…17 Recently a new ground-breaking cloud profiling radar named GRaCE was published, using pulsed operation at 199.5 GHz with solid state components and capable of measuring Doppler velocities up to ±9.38 m/s. 18 Doppler capable radar systems at G-band remain scarce.…”