kasacrcrraster (a1)

The Ka-Band Scanning ARM Cloud Radar (KASACR) records cloud properties. ARM's scanning cloud radars are 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 (1.7 kW peak power) or an X-band (20 kW peak power). Beamwidths for Ka-bands paired with W-bands are roughly matched at 0.3 degrees. The X-band beamwidth is approximately 1 degree. Due to the narrow antenna beamwidth, ARM’s scanning cloud radars use scanning strategies 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 KASACR are copolar and cross-polar radar reflectivity, Doppler velocity, spectra width and spectra when not scanning, and linear depolarization ratio. KASACR data from the 2018–2019 Cloud, Aerosol, and Complex Terrain Interactions (CACTI) field campaign in Argentina are now available as b1-level products. Building on the original CACTI operational data, the b1-level products feature improved data quality resulting from extensive analyses and corrections. The data are cross-calibrated to a common point, datastreams are corrected for operational issues that occurred during the campaign, and several data quality masks and basic derived products are incorporated. For more information, read the CACTI radar b1-level processing report.

Ka波段扫描ARM云雷达（Ka-Band Scanning ARM Cloud Radar，KASACR）用于记录云的相关属性。ARM扫描云雷达为搭载于同一扫描转台的双频、双极化多普勒雷达。每台转台包含一台Ka波段雷达（峰值功率2kW），而部署位置决定了另一台雷达为W波段（峰值功率1.7kW）还是X波段（峰值功率20kW）。与W波段搭配的Ka波段波束宽度大致匹配，约为0.3°；X波段波束宽度约为1°。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不同的扫描策略：KASACR并未聚焦于平面位置指示（Plan Position Indicator，PPI）扫描，而是在多个方位角下采用距离高度指示（Range Height Indicator，RHI）扫描以获取云体三维数据。KASACR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。2018—2019年在阿根廷开展的云、气溶胶与复杂地形相互作用（Cloud, Aerosol, and Complex Terrain Interactions，CACTI）野外试验的KASACR数据现已以b1级产品形式发布。相较于原始CACTI业务数据，b1级产品通过全面的分析与校正提升了数据质量：数据已交叉校准至统一基准，针对试验期间出现的业务问题对数据流进行了校正，并集成了多套数据质量掩码及基础衍生产品。如需了解更多信息，请参阅《CACTI雷达b1级处理报告》。