W-Band ARM Scanning Cloud Radar (WSACR); Zenith Pointing PPI Scan - wsacr2cfrzppi

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 (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. \n \nDue 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 Ka-SACR uses range height indicator, or RHI, scans at numerous azimuths to obtain cloud volume data. \n \nMeasurements collected with the W-SACR are copolar and cross-polar radar reflectivity, Doppler velocity, spectra width and spectra when not scanning, and linear depolarization ration.

ARM扫描式云雷达为搭载于统一扫描基座的全相干双频双极化多普勒雷达。每套扫描基座均配备一部Ka波段雷达（峰值功率2kW），其部署位置决定了第二部雷达为W波段（WSACR；峰值功率1.7kW）或X波段（XSACR；峰值功率20kW）。Ka波段与W波段的波束宽度大致匹配，均约为0.3度。

由于天线波束宽度极窄，ARM扫描式云雷达采用区别于常规天气雷达的扫描策略。Ka波段扫描云雷达（Ka-SACR）并未聚焦于平面位置指示（PPI）扫描模式，而是在多个方位角下采用距离高度指示（RHI）扫描以获取云体体积数据。

W波段扫描云雷达（W-SACR）采集的测量数据包括同极化与交叉极化雷达反射率、多普勒速度、非扫描状态下的谱宽与频谱，以及线性退极化比。