W-Band ARM Scanning Cloud Radar (WSACR); PPI Volume Scan - wsacr2cfrppiv

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扫描云雷达为搭载于统一扫描基座的全相干双频双偏振多普勒雷达。每套基座均配备一台Ka波段雷达（峰值功率2kW），其部署位置将决定第二台雷达的频段：若为W波段则为WSACR（峰值功率1.7kW），若为X波段则为XSACR（峰值功率20kW）。Ka波段与W波段的波束宽度均约为0.3度，二者大致匹配。 由于天线波束宽度极窄，ARM扫描云雷达采用与常规天气雷达迥异的扫描策略。Ka波段扫描云雷达（Ka-SACR）并未以平面位置指示（plan position indicator, PPI）扫描为核心工作模式，而是在多个方位角上执行距离高度指示（range height indicator, RHI）扫描，以此获取云体三维数据。 W波段扫描云雷达（W-SACR）所采集的测量参数包括同极化与交叉极化雷达反射率、多普勒速度、谱宽、非扫描状态下的频谱以及线性退极化比。