kasacrvpthrc (b1)

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）用于记录云系特性。ARM旗下的扫描型云雷达均为搭载于共用扫描转台的双频双极化多普勒雷达，每套转台均配备一台Ka波段雷达（峰值功率2千瓦），第二台雷达的类型则根据部署场地而定，可为峰值功率1.7千瓦的W波段雷达，或峰值功率20千瓦的X波段雷达。与W波段配对的Ka波段波束宽度约为0.3度，二者波束宽度大致匹配；X波段波束宽度则约为1度。鉴于天线波束宽度极窄，ARM旗下的扫描型云雷达采用了区别于常规气象雷达的扫描方案：KASACR并未以平面位置指示器（Plan Position Indicator，PPI）扫描为核心扫描模式，而是在多个方位角下采用距离高度显示器（Range Height Indicator，RHI）扫描，以获取完整的云体三维数据。KASACR采集的观测参数包括同极化与交叉极化雷达反射率、多普勒速度、频谱宽度，以及非扫描状态下的频谱与线性退偏振比。目前，2018至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）外场试验所获取的KASACR数据，已以b1级数据产品的形式对外发布。该b1级产品以原始CACTI运行数据为基础，通过全面的分析与校正流程提升了数据质量：数据已被交叉校准至统一基准点，数据流针对试验期间出现的各类运行问题完成了校正，同时集成了多套数据质量掩码与基础衍生数据产品。如需了解更多细节，请参阅《CACTI雷达b1级数据处理报告》。