ARM’s scanning cloud radars are fully coherent dual-frequency, dual-polarization Doppler radars mounted on a common scanning pedestal. Each pedestal includes a Ka-band radar (KASACR; 2kW peak power), and the deployment location determines whether the second radar is a W-band (WSACR; 1.7 kW peak power) or X-band (XSACR; 20 kW peak power). Beamwidths at Ka and W bands are roughly matched at 0.3 degrees.
Due to the narrow antenna beamwidth, ARM’s scanning cloud radars use scanning strategies that are unlike typical weather radars. Rather than focusing on plan position indicator, or PPI, scans, the KASACR uses range height indicator, or RHI, scans at numerous azimuths to obtain cloud volume data.
Measurements collected with the WSACR are copolar and crosspolar radar reflectivity, Doppler velocity, spectra width and spectra when not scanning, and linear depolarization ratio.
For the 2019–2020 Cold-Air Outbreaks in the Marine Boundary Layer Experiment (COMBLE) in Norway, ARM deployed a KASACR, WSACR, and Ka-Band ARM Zenith Radar (KAZR). Data from these radars are now available as b1-level products featuring improved data quality. These b1-level products were created by cross-calibrating the radars to a common point, and they contain ground clutter and data quality masks. For more information, read the COMBLE radar b1-level processing report.